Difference between revisions of "Team:EPF Lausanne/Notebook/Ecoli"
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<div class="col-sm-9"> | <div class="col-sm-9"> | ||
− | <!-- CONSTRUCTION PDCAS9-W | + | <!-- CONSTRUCTION PDCAS9-W --> |
<section id="pdcas9w" class="panel"> | <section id="pdcas9w" class="panel"> | ||
− | <h1>Construction of pdCas9-w</br><small> | + | <h1>Construction of pdCas9-w</br><small>07.05.2015 - 01.06.2015</small></h1> |
<p>pdCas9-w contains a gene that produces dCas9 fused to the w subunit of RNA polymerase (RNAP), which recruits RNAP.</p> | <p>pdCas9-w contains a gene that produces dCas9 fused to the w subunit of RNA polymerase (RNAP), which recruits RNAP.</p> | ||
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<div id="PCRpdcas9" class="panel"> | <div id="PCRpdcas9" class="panel"> | ||
− | <h3>Open pdCas9 by PCR</br><small> | + | <h3>Open pdCas9 by PCR</br><small>07.05.2015, 10.05.2015</small></h3> |
<div class="row"> | <div class="row"> | ||
<div class="col-md-7"> | <div class="col-md-7"> | ||
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<div id="PCRpwj66" class="panel"> | <div id="PCRpwj66" class="panel"> | ||
− | <h3>Extract w subunit from pWJ66 by PCR</br> | + | <h3>Extract w subunit from pWJ66 by PCR</br><small>07.05.2015</small></h3> |
<div class="row"> | <div class="row"> | ||
<div class="col-md-7"> | <div class="col-md-7"> | ||
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<div id="gibsonpdcas9w" class="panel"> | <div id="gibsonpdcas9w" class="panel"> | ||
− | <h3>Gibson assembly of pdCas9-w</br> | + | <h3>Gibson assembly of pdCas9-w</br><small>Gibson assembly, transformation: 19.05.2015. Colony PCR: 29.05.2015. Restriction analysis: 01.06.2015.</small></h3> |
− | + | ||
<div class="row"> | <div class="row"> | ||
<div class="col-md-7"> | <div class="col-md-7"> | ||
− | <p> | + | <p>Colony PCR yields 666 bp amplicons if Gibson assembly worked and 396 bp amplicons if the plasmid self-ligated.</br>Lane "C" is a negative control: PCR was run with all components except template DNA. It is empty which means there is no contamination.</br>Gibson assembly seems to have worked for some samples. (cf. Fig.3)</br>To avoid working with too many samples, we kept the ones from lanes 16, 22, 25, 31, 37 and 43 for the next steps. We did overnight liquid cultures of these colonies.</p> |
+ | <p>pdCas9-w was analysed by restriction digest with BamHI and KpnI, both single cutters in pdCas9 and double cutters in pdCas9-w (cf. Fig.4).</br> Too much ladder was loaded so it is difficult to estimate the size of the fragments. The smaller fragments are also very difficult to see. By looking at the relative heights, we can say that all colonies seem to have the w subunit insert. There is only the undigested sample for colony 16 that is not visible, probably due to an error while loading the gel.</p> | ||
+ | <p>Sequencing confirmed that sample 22 is in fact pdCas9-w. We used this sample for the next steps and stored it as a glycerol stock (c.f. Protocols).</p> | ||
</div> | </div> | ||
<div class="col-md-5"> | <div class="col-md-5"> | ||
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<figcaption><b>Fig.3</b> - Gels of colony PCR of dCas9-w Gibson assembly products</figcaption> | <figcaption><b>Fig.3</b> - Gels of colony PCR of dCas9-w Gibson assembly products</figcaption> | ||
</figure> | </figure> | ||
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<figure> | <figure> | ||
<a href="https://static.igem.org/mediawiki/2015/0/0a/Lab_nb_ecoli_fig4a.jpg"><img src="https://static.igem.org/mediawiki/2015/0/0a/Lab_nb_ecoli_fig4a.jpg" alt="Figure 4a" style="height:120px"></a> | <a href="https://static.igem.org/mediawiki/2015/0/0a/Lab_nb_ecoli_fig4a.jpg"><img src="https://static.igem.org/mediawiki/2015/0/0a/Lab_nb_ecoli_fig4a.jpg" alt="Figure 4a" style="height:120px"></a> | ||
<a href="https://static.igem.org/mediawiki/2015/0/0a/Lab_nb_ecoli_fig4b.jpg"><img src="https://static.igem.org/mediawiki/2015/0/0a/Lab_nb_ecoli_fig4b.jpg" alt="Figure 4b" style="height:120px"></a> | <a href="https://static.igem.org/mediawiki/2015/0/0a/Lab_nb_ecoli_fig4b.jpg"><img src="https://static.igem.org/mediawiki/2015/0/0a/Lab_nb_ecoli_fig4b.jpg" alt="Figure 4b" style="height:120px"></a> | ||
<a href="https://static.igem.org/mediawiki/2015/9/9c/Lab_nb_ecoli_fig4c.jpg"><img src="https://static.igem.org/mediawiki/2015/9/9c/Lab_nb_ecoli_fig4c.jpg" alt="Figure 4c" style="height:120px"></a> | <a href="https://static.igem.org/mediawiki/2015/9/9c/Lab_nb_ecoli_fig4c.jpg"><img src="https://static.igem.org/mediawiki/2015/9/9c/Lab_nb_ecoli_fig4c.jpg" alt="Figure 4c" style="height:120px"></a> | ||
− | <figcaption><b>Fig.4</b> - Gels of restriction digest of pdCas9-w Gibson assembly products</figcaption> | + | <figcaption><b>Fig.4</b> - Gels of restriction digest of pdCas9-w Gibson assembly products. Each colony is present on gels in triplicates: undigested (7kb but migrates faster than linear DNA), digested by BamHI (6147 bp + 834 bp) and digested by KpnI (4534 bp + 2447 bp).</figcaption> |
</figure> | </figure> | ||
</div> | </div> | ||
</div> | </div> | ||
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</div> | </div> | ||
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<!--CONSTRUCTION PDCAS9-W-SGRNAS ++ --> | <!--CONSTRUCTION PDCAS9-W-SGRNAS ++ --> | ||
<section id="pdcas9wsgrna" class="panel"> | <section id="pdcas9wsgrna" class="panel"> | ||
− | <h1>Construction of pdCas9-w-sgRNAs - | + | <h1>Construction of pdCas9-w-sgRNAs - 08.07.2015 - 02.09.2015</h1> |
<div class="row"> | <div class="row"> | ||
<div class="col-md-7"> | <div class="col-md-7"> | ||
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<h2>Results</h2> | <h2>Results</h2> | ||
<div id="part1" class="panel"> | <div id="part1" class="panel"> | ||
− | <h3>Part 1: Assemble pdCas9-w + sgRNA</h3> | + | <h3>Part 1: Assemble pdCas9-w + sgRNA</br><small>08.07.2015 - 07.08.2015</h3> |
<div id="openpdcas9w"> | <div id="openpdcas9w"> | ||
− | <h4>Open pdCas9-w by restriction digest</br><small> | + | <h4>Open pdCas9-w by restriction digest</br><small>16.07.2015, 19.07.2015, 26.07.2015, 02.08.2015 (repeats)</small></h4> |
<div class="row"> | <div class="row"> | ||
<div class="col-md-7"> | <div class="col-md-7"> | ||
− | <p>The digested and undigested plasmids have the same size. Circular fragments migrates faster than linear fragments of the same size. This means that the undigested plasmid will migrate faster than the digested plasmid.</br>Even though the ladder is not clear, by looking at the relative heights we can see that the digested sample migrated more slowly than the undigested sample (cf. Fig.9). The restriction digest was successful.</p> | + | <p>The digested and undigested plasmids have the same size. Circular fragments migrates faster than linear fragments of the same size. This means that the undigested plasmid will migrate faster than the digested plasmid.</br>Even though the ladder is not clear, by looking at the relative heights we can see that the digested sample migrated more slowly than the undigested sample (cf. Fig.9). The restriction digest was successful.</br>Diegestion was repeated at least 3 times, we needed it for many PCRs.</p> |
</div> | </div> | ||
<div class="col-md-5"> | <div class="col-md-5"> | ||
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</div> | </div> | ||
<div id="pcrsgrna"> | <div id="pcrsgrna"> | ||
− | <h4>Amplify sgRNA cassettes by PCR</br><small> | + | <h4>Amplify sgRNA cassettes by PCR</br><small>08.07.2015, 09.07.2015, 10.07.2015, 13.07.2015, 14.07.2015, 15.07.2015, 16.07.2015, 02.08.2015, 03.08.2015, 04.08.2015, 06.08.2015</small></h4> |
<div class="row"> | <div class="row"> | ||
<div class="col-md-6"> | <div class="col-md-6"> | ||
<p>Amplified sgRNA cassettes are expected to be about 370 bp.</br>sgRNA cassette Z0 was amplified with Q5 PCR. Both samples were successfully amplified (cf. Fig.10a).</br>sgRNA cassette Z4 was amplified with Phusion PCR. Samples 3 and 4 were successfuly amplified (cf. Fig.10b).</br>sgRNA cassette Z35 was successfuly amplified with Phusion PCR. However, it is not easily visible on the gel. (cf. Fig.10c)</br>sgRNA cassette X0 was successfuly amplified with Phusion PCR. (cf. Fig.10d)</br>sgRNA cassette X4 was successfuly amplified with Phusion PCR. (cf. Fig.10e)</br>sgRNA cassette X35 was successfuly amplified with Phusion PCR. (cf. Fig.10f)</p> | <p>Amplified sgRNA cassettes are expected to be about 370 bp.</br>sgRNA cassette Z0 was amplified with Q5 PCR. Both samples were successfully amplified (cf. Fig.10a).</br>sgRNA cassette Z4 was amplified with Phusion PCR. Samples 3 and 4 were successfuly amplified (cf. Fig.10b).</br>sgRNA cassette Z35 was successfuly amplified with Phusion PCR. However, it is not easily visible on the gel. (cf. Fig.10c)</br>sgRNA cassette X0 was successfuly amplified with Phusion PCR. (cf. Fig.10d)</br>sgRNA cassette X4 was successfuly amplified with Phusion PCR. (cf. Fig.10e)</br>sgRNA cassette X35 was successfuly amplified with Phusion PCR. (cf. Fig.10f)</p> | ||
+ | <p>Many PCRs were necessary to obtain all sgRNAs because of technical problems, such as PCR reactions not working and contamination of most of our tubes. Figures show only the samples that were used in the next steps.</p> | ||
</div> | </div> | ||
<div class="col-md-6"> | <div class="col-md-6"> | ||
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</div> | </div> | ||
<div id="gibsonpdcas9wsgrna"> | <div id="gibsonpdcas9wsgrna"> | ||
− | <h4>Assemble pdCas9-w-sgRNA constructs | + | <h4>Assemble pdCas9-w-sgRNA constructs</br><small>Gibson assembly, transformation: 16.07.2015, 17.07.2015, 27.07.2015, 28.07.2015, 29.07.2015, 04.08.2015, 05.08.2015</br> Colony PCR: 17.07.2015, 26.07.2015, 27.07.2015, 28.07.2015, 29.07.2015, 30.07.2015, 05.08.2015, 06.08.2015, 07.08.2015</h4> |
<div class="row"> | <div class="row"> | ||
<div class="col-md-7"> | <div class="col-md-7"> | ||
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<div id="part2" class="panel"> | <div id="part2" class="panel"> | ||
− | <h3>Part 2: Assemble pdCas9-w-sgRNA + sgRNA</h3> | + | <h3>Part 2: Assemble pdCas9-w-sgRNA + sgRNA</br><small>24.08.2015 - 02.09.2015</small></h3> |
<div id="pcrpdcas9sgrna"> | <div id="pcrpdcas9sgrna"> | ||
− | <h4>Extract sgRNA from pdCas9-w-sgRNA and open pdCas9-w-sgRNA by Q5 PCR</h4> | + | <h4>Extract sgRNA from pdCas9-w-sgRNA and open pdCas9-w-sgRNA by Q5 PCR</br><small>24.08.2015, 25.08.2015, 28.08.2015, 31.08.2015</small></h4> |
<div class="row"> | <div class="row"> | ||
<div class="col-md-6"> | <div class="col-md-6"> | ||
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</div> | </div> | ||
<div id="gibsonpdcas9wsgrna2"> | <div id="gibsonpdcas9wsgrna2"> | ||
− | <h4>Assemble pdCas9-w-sgRNA-sgRNA constructs</h4> | + | <h4>Assemble pdCas9-w-sgRNA-sgRNA constructs</br><small>Gibson assembly, transformation: 26.08.2015, 31.08.2015. Colony PCR: 31.08.2015, 02.09.2015</small></h4> |
<div class="row"> | <div class="row"> | ||
<div class="col-md-6"> | <div class="col-md-6"> | ||
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</section> | </section> | ||
− | <!--CONSTRUCTION PWJ89ALT | + | <!--CONSTRUCTION PWJ89ALT--> |
<section id="pwj89alt" class="panel"> | <section id="pwj89alt" class="panel"> | ||
− | <h1>Construction of pWJ89alt</h1> | + | <h1>Construction of pWJ89alt</br><small>05.08.2015 - 13.08.2015</small></h1> |
<p>pWJ89alt contains GFP controlled by the promoter J23117alt, which can be activated by dCas9-w bound to sgRNA X4 and inhibited by dCas9-w bound to sgRNA X0 or X35.</p> | <p>pWJ89alt contains GFP controlled by the promoter J23117alt, which can be activated by dCas9-w bound to sgRNA X4 and inhibited by dCas9-w bound to sgRNA X0 or X35.</p> | ||
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<div id="pcrpwj89" class="panel"> | <div id="pcrpwj89" class="panel"> | ||
− | <h3>PCR pWJ89</h3> | + | <h3>PCR pWJ89</br><small>05.08.2015</small></h3> |
<div class="row"> | <div class="row"> | ||
<div class="col-md-7"> | <div class="col-md-7"> | ||
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<div id="pcrj23117alt" class="panel"> | <div id="pcrj23117alt" class="panel"> | ||
− | <h3>PCR J23117alt promoter</h3> | + | <h3>PCR J23117alt promoter</br><small>05.08.2015</small></h3> |
<div class="row"> | <div class="row"> | ||
<div class="col-md-7"> | <div class="col-md-7"> | ||
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<div id="gibsonpwj89alt" class="panel"> | <div id="gibsonpwj89alt" class="panel"> | ||
− | <h3>Gibson assembly of pWJ89alt</h3> | + | <h3>Gibson assembly of pWJ89alt</br><small>Gibson assembly, transformation: 10.08.2015, Colony PCR: 11.08.2015</small></h3> |
<p>Colony PCR showed two colonies for which Gibson assembly worked. However, images of gels of colony PCR were lost for technical reasons.</br>Sequencing confirmed that both colonies were in fact pWJ89alt and that one had a deletion but the other one did not have any mutations. We kept the mutation-free colony and stored it in a Glycerol stock (cf. Protocols).</p> | <p>Colony PCR showed two colonies for which Gibson assembly worked. However, images of gels of colony PCR were lost for technical reasons.</br>Sequencing confirmed that both colonies were in fact pWJ89alt and that one had a deletion but the other one did not have any mutations. We kept the mutation-free colony and stored it in a Glycerol stock (cf. Protocols).</p> | ||
</div> | </div> | ||
− | |||
</section> | </section> | ||
<!--CONSTRUCTION PARAC-SGRNA--> | <!--CONSTRUCTION PARAC-SGRNA--> | ||
<section id="arac" class="panel"> | <section id="arac" class="panel"> | ||
− | <h1>Construction of pAraC-sgRNA</br><small> | + | <h1>Construction of pAraC-sgRNA</br><small>25.08.2015 - 03.09.2015</small></h1> |
<p>We made 3 pAraC-sgRNA constructs: pAraC-Z0 and pAraC-Z4 contain sgRNA Z0 or Z4 producing cassettes controlled by promoter pBAD-AraC (positively regulated by arabinose) and pAraC-Z0-Z4 contains sgRNA Z0 producing cassette controlled by promoter pBAD-AraC and sgRNA Z4 producing cassette controlled by promoter pBAD (constitutively active).</p> | <p>We made 3 pAraC-sgRNA constructs: pAraC-Z0 and pAraC-Z4 contain sgRNA Z0 or Z4 producing cassettes controlled by promoter pBAD-AraC (positively regulated by arabinose) and pAraC-Z0-Z4 contains sgRNA Z0 producing cassette controlled by promoter pBAD-AraC and sgRNA Z4 producing cassette controlled by promoter pBAD (constitutively active).</p> | ||
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<h2>Results</h2> | <h2>Results</h2> | ||
<div id="pcrparac"> | <div id="pcrparac"> | ||
− | <h3>PCR pAraC and sgRNA</br><small> | + | <h3>PCR pAraC and sgRNA</br><small>25.08.2015, 26.08.2015</small></h3> |
<div class="row"> | <div class="row"> | ||
<div class="col-md-7"> | <div class="col-md-7"> | ||
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</div> | </div> | ||
<div id="gibsonparac"> | <div id="gibsonparac"> | ||
− | <h3>Assemble pAraC-sgRNA constructs</br><small>Gibson assembly and transformation: 08 | + | <h3>Assemble pAraC-sgRNA constructs</br><small>Gibson assembly and transformation: 28.08.2015, 01.09.2015, Colony PCR: 31.08.2015, 02.09.2015</h3> |
<p>Colony PCR (pictures of gels were lost for technical reasons) and seqeuncing confirmed Gibson assembly was successful for one colony for each construct.</p> | <p>Colony PCR (pictures of gels were lost for technical reasons) and seqeuncing confirmed Gibson assembly was successful for one colony for each construct.</p> | ||
</div> | </div> | ||
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<!--CONSTRUCTION PWJ89ALT-Z4-TO-X4--> | <!--CONSTRUCTION PWJ89ALT-Z4-TO-X4--> | ||
<section id="plink" class="panel"> | <section id="plink" class="panel"> | ||
− | <h1>Construction of pWJ89alt_Z4-to-X4</br><small> | + | <h1>Construction of pWJ89alt_Z4-to-X4</br><small>18.08.2015 - 02.09.2015</small></h1> |
<p>pWJ89alt_Z4-to-X4 contains a cassette producing sgRNA X4 (activator for J23117alt) controlled by the promoter J23117 and GFP under the J23117alt promoter (corresponds to pWJ89alt).</p> | <p>pWJ89alt_Z4-to-X4 contains a cassette producing sgRNA X4 (activator for J23117alt) controlled by the promoter J23117 and GFP under the J23117alt promoter (corresponds to pWJ89alt).</p> | ||
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<div id="openpwj89alt" class="panel"> | <div id="openpwj89alt" class="panel"> | ||
− | <h3>Open pWJ89alt by restriction digest</br><small> | + | <h3>Open pWJ89alt by restriction digest</br><small>18.08.2015</small></h3> |
<div class="row"> | <div class="row"> | ||
<div class="col-md-7"> | <div class="col-md-7"> | ||
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<div id="pcrz4-to-x4" class="panel"> | <div id="pcrz4-to-x4" class="panel"> | ||
− | <h3>PCR Z4-to-X4</br><small> | + | <h3>PCR Z4-to-X4</br><small>19.08.2015</small></h3> |
<div class="row"> | <div class="row"> | ||
<div class="col-md-7"> | <div class="col-md-7"> | ||
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<div id="#gibsonplink" class="panel"> | <div id="#gibsonplink" class="panel"> | ||
− | <h3>Gibson assembly pWJ89alt_Z4-to-X4</br><small>Gibson assembly and transformation: 08 | + | <h3>Gibson assembly pWJ89alt_Z4-to-X4</br><small>Gibson assembly and transformation: 28.08.2015, Colony PCR: 31.08.2015</small></h3> |
</div> | </div> | ||
</section> | </section> |
Revision as of 15:47, 13 September 2015
Construction of pdCas9-w07.05.2015 - 01.06.2015
pdCas9-w contains a gene that produces dCas9 fused to the w subunit of RNA polymerase (RNAP), which recruits RNAP.
Materials and method
- Open pdCas9-bacteria by Phusion PCR (cf. Protocols) with primers f_Gbs_pdCas9 and r_Gbs_pdCas9 + PCR product purification (cf. Protocols) + agarose gel electrophoresis of 2 µL purified PCR products (with 1kb Generuler ladder)pdCas9-bacteria was a gift from Stanley Qi (Addgene plasmid # 44249).
- Extract w subunit from pWJ66 by Phusion PCR (cf. Protocols) with primers f_Gbs_w and r_Gbs_w + PCR product purification (cf. Protocols) + agarose gel electrophoresis of 2 µL purified PCR products (with 1kb Generuler)pWJ66 was a gift from Luciano Marraffini (Addgene plasmid # 46570).
- Gibson assembly (cf. Protocols) of pdCas9-w using purified PCR products of pdCas9-bacteria and w subunit + transformation (cf. Protocols) of ultra-competent DH5a cells (NEB)Control with colony PCR (cf. Protocols) with primers f_Gbs_w and r_Scq_pdCas9_w_sgRNA primers + agarose gel electrophoresis of 2 µL PCR products (with 1kb Generuler) + restriction digest (Cf. Protocols) of pdCas9-w (isolated by Miniprep (cf.Protocols)) with BamHI and KpnI seperately + agarose gel electrophoresis of 2 µL digested products (with 1kb Generuler) + sequencing (Microsynth)
- Site-directed mutagenesis (cf. Protocols) of dCas9-w with primers f_Mt_A2080C_pdCas9-w and r_Mt_A2080C_pdCas9-w (necesary for pdCas9-w to be BioBrick compatible)Control with restriction digest (cf. Protocols) of mutated pdCas9-w (isolated by Miniprep (cf. Protocols)) with EcoRI + sequencing (Microsynth)
Results
Open pdCas9 by PCR07.05.2015, 10.05.2015
Linearized pdCas9-w is expected to be 6705 bp.We tested many parameters: HF vs. GC buffer, different annealing temperatures and different extension times. Many, but not all, of our samples were successfully amplified (cf. Fig.1).For next steps, sample from lane 1 (cf. Fig.1) was used.
Extract w subunit from pWJ66 by PCR07.05.2015
Successful PCR reactions are expected to yield 340 bp fragments.PCR was succesful for sample visible on gel. (cf. Fig.2)
Gibson assembly of pdCas9-wGibson assembly, transformation: 19.05.2015. Colony PCR: 29.05.2015. Restriction analysis: 01.06.2015.
Colony PCR yields 666 bp amplicons if Gibson assembly worked and 396 bp amplicons if the plasmid self-ligated.Lane "C" is a negative control: PCR was run with all components except template DNA. It is empty which means there is no contamination.Gibson assembly seems to have worked for some samples. (cf. Fig.3)To avoid working with too many samples, we kept the ones from lanes 16, 22, 25, 31, 37 and 43 for the next steps. We did overnight liquid cultures of these colonies.
pdCas9-w was analysed by restriction digest with BamHI and KpnI, both single cutters in pdCas9 and double cutters in pdCas9-w (cf. Fig.4). Too much ladder was loaded so it is difficult to estimate the size of the fragments. The smaller fragments are also very difficult to see. By looking at the relative heights, we can say that all colonies seem to have the w subunit insert. There is only the undigested sample for colony 16 that is not visible, probably due to an error while loading the gel.
Sequencing confirmed that sample 22 is in fact pdCas9-w. We used this sample for the next steps and stored it as a glycerol stock (c.f. Protocols).
Site-directed mutagenesis of dCas9-w - (date?)
Construction of pdCas9-w-sgRNAs - 08.07.2015 - 02.09.2015
These experiments consist of inserting one or two sgRNA producing cassettes (cf. Fig.8) into pdCas9-w. In part 1, one sgRNA (X0, X4, X35, Z0, Z4 or Z35) was inserted into pdCas9-w by Gibson assembly. For technical reasons, we were unable to make most constructs with two inserted cassettes using this method. In part 2, we extracted sgRNA cassettes from existing constructs and inserted them in other constructs that already contained one other sgRNA cassette.
Materials and method
Part 1: Assemble pdCas9-w + sgRNA
- Open pdCas9-w by restriction digest (cf. Protocols) with BsrBI (blunt ends) + agarose gel electrophoresis of 2 µL of digested and undigested product (with 1kb Generuler)
- Amplify sgRNA cassettes by Phusion or Q5 PCR (cf. Protocols) with primers f_Gbs_sgRNA-A and r_Gbs_sgRNA-B + agarose gel electrophoresis of 2 µL PCR products (with 1kb Generuler) + PCR product purification (cf. Protocols).
- Gibson assembly pdCas9-w-sgRNA (cf. Protocols) with linearized pdCas9-w and purified sgRNA PCR products + transformation (cf. Protocols) of ultra-competent DH5a cells (NEB)Control with colony PCR (cf. Protocols) with primers f_ColPCR_sgRNAs and r_ColPCR_sgRNAs + agarose gel electrophoresis of 2 µL PCR prodcuts (with 1kb Generuler) (one colony PCR (cf. Fig11a) was done with primers f_Gbs_pdCas9 and r_Scq_pdCas9_w_sgRNA) + sequencing (Microsynth)
Part 2: Assemble pdCas9-w-sgRNA + sgRNA
- Extract sgRNA from pdCas9-w-sgRNA by Q5 PCR (cf. Protocols) with primers f_Gbs_sgRNAinPd and r_Gbs_sgRNAinPd + agarose gel electrophoresis of 2 µL PCR products (with 1kb Generuler) + PCR product purification (cf. Protocols)
- Open pdCas9-w-sgRNA by Q5 PCR (cf. Protocols) with primers f_opn_d9w and r_opn_d9w + agarose gel electrophoresis of 2 µL PCR products (with 1kb Generuler) + PCR product purification (cf. Protocols)
- Gibson assembly of pdCas9-w-sgRNA, as describes in table below, + transformation (cf. Protocols) of ultra-competent DH5a cells (NEB)Control with colony PCR (cf. Protocols) with primers f_Sq_CoP_pdCas92ndIns and r_Sq_CoP_pAraC2ndInsert + agarose gel electrophoresis of 2 µL PCR prodcuts (with 1kb Generuler or 2-log DNA ladder) + sequencing (Microsynth)
sgRNA insert | sgRNA in pdCas9-w-sgRNA (backbone) |
---|---|
Z4 | pdCas9-w-Z0 |
Z35 | pdCas9-w-Z0 |
Z35 | pdCas9-w-Z4 |
X4 | pdCas9-w-X0 |
X35 | pdCas9-w-X0 |
X35 | pdCas9-w-X4 |
Results
Part 1: Assemble pdCas9-w + sgRNA08.07.2015 - 07.08.2015
Open pdCas9-w by restriction digest16.07.2015, 19.07.2015, 26.07.2015, 02.08.2015 (repeats)
The digested and undigested plasmids have the same size. Circular fragments migrates faster than linear fragments of the same size. This means that the undigested plasmid will migrate faster than the digested plasmid.Even though the ladder is not clear, by looking at the relative heights we can see that the digested sample migrated more slowly than the undigested sample (cf. Fig.9). The restriction digest was successful.Diegestion was repeated at least 3 times, we needed it for many PCRs.
Amplify sgRNA cassettes by PCR08.07.2015, 09.07.2015, 10.07.2015, 13.07.2015, 14.07.2015, 15.07.2015, 16.07.2015, 02.08.2015, 03.08.2015, 04.08.2015, 06.08.2015
Amplified sgRNA cassettes are expected to be about 370 bp.sgRNA cassette Z0 was amplified with Q5 PCR. Both samples were successfully amplified (cf. Fig.10a).sgRNA cassette Z4 was amplified with Phusion PCR. Samples 3 and 4 were successfuly amplified (cf. Fig.10b).sgRNA cassette Z35 was successfuly amplified with Phusion PCR. However, it is not easily visible on the gel. (cf. Fig.10c)sgRNA cassette X0 was successfuly amplified with Phusion PCR. (cf. Fig.10d)sgRNA cassette X4 was successfuly amplified with Phusion PCR. (cf. Fig.10e)sgRNA cassette X35 was successfuly amplified with Phusion PCR. (cf. Fig.10f)
Many PCRs were necessary to obtain all sgRNAs because of technical problems, such as PCR reactions not working and contamination of most of our tubes. Figures show only the samples that were used in the next steps.
Assemble pdCas9-w-sgRNA constructsGibson assembly, transformation: 16.07.2015, 17.07.2015, 27.07.2015, 28.07.2015, 29.07.2015, 04.08.2015, 05.08.2015 Colony PCR: 17.07.2015, 26.07.2015, 27.07.2015, 28.07.2015, 29.07.2015, 30.07.2015, 05.08.2015, 06.08.2015, 07.08.2015
In colony PCR, primers were placed such as amplicons are 445 bp if the plasmid self-ligated, 723 bp if Gibson assembly of 1 sgRNA cassette worked and 1120 bp if Gibson assembly of 2 sgRNA cassettes worked.
pdCas9-w-Z0 was obtained by a faulty assembly of pdCas9-w-Z0-Z4 that only took up 1 of the 2 sgRNA cassettes. Sample 20 of the colony PCR (cf. Fig.11a) was confirmed by sequencing to be pdCas9-w-Z0 and to not contain any mutations that may have an effect on its activity. Sample 13 seems to be pdCas9-w-Z0-Z4 according to colony PCR (cf. Fig.11a), but sequencing showed that it is pdCas9-w-X0-Z0, probably due to contamination of a tube. (This sample will be used again in Part 2.)Colony PCR showed that all colonies tested for pdCas9-w-Z4 have the inserted sgRNA cassette (cf. Fig.11b). Sequencing comfirmed that sample 5 is in fact pdCas9-w-Z4. Colony PCR showed that the Gibson assembly for sample 5 of pdCas9-w-Z35 seems to have worked (cf. Fig.11c) and sequencing confirmed that is the case. Sequencing also showed some mutations or deletions in the promoter and/or terminator for these 2 samples. We decided to keep working with these and test whether these mutations are significative with an activity assay.Colony PCR and sequencing showed that Gibson assembly was successful for sample 5 of pdCas9-w-X0 (cf. Fig.11d). However, it contains a mutation in the promoter. A 2nd pdCas9-w-X0 without mutations will be constructed in part 2, after which we will be able to compare the activity of this promoter with/without a mutation.Colony PCR of pdCas9-w-X4 showed many potentially good samples (cf. Fig.11e). Sequencing of sample 10 confirmed that it is in fact pdCas9-w-X4 and that it does not contain any mutations.Colony PCR and sequencing showed that Gibson assembly was successful for the colony of pdCas9-w-X35 (cf. Fig.11d) and no mutations were found in the sequence.
Part 2: Assemble pdCas9-w-sgRNA + sgRNA24.08.2015 - 02.09.2015
Extract sgRNA from pdCas9-w-sgRNA and open pdCas9-w-sgRNA by Q5 PCR24.08.2015, 25.08.2015, 28.08.2015, 31.08.2015
Amplified sgRNA cassettes (Z4, Z35, X4 and X35) are expected to be 400 bp. All were successfully amplified (cf. Fig.12a and Fig.12b).Amplified pdCas9-w-sgRNA (Z0, Z4, X0 and X4) are expected to be about 7000 bp. All were successfully amplified (cf. Fig.12a and Fig.12b).
Assemble pdCas9-w-sgRNA-sgRNA constructsGibson assembly, transformation: 26.08.2015, 31.08.2015. Colony PCR: 31.08.2015, 02.09.2015
Colony PCR primers are placed such as amplicons are 724 bp if Gibson assembly worked and are 390 bp if it did not (self-ligation). All necessary constructs were successfuly obtained. Following colonies were kept for our constructs: colony #1 for pdCas9-w-Z0-Z4 (cf. Fig.13a), colony #4 (2nd attempt) for pdCas9-w-Z0-Z35 (cf. Fig.13c), colony #6 for pdCas9-w-Z4-Z35 (cf. Fig.13b), colony #4 for pdCas9-w-X0-X4 (cf. Fig.13c), colony #2 for pdCas9-w-X0-X35 (cf. Fig.13d) and colony #1 for pdCas9-w-X4-X35 (cf. Fig.13e).
Construction of pWJ89alt05.08.2015 - 13.08.2015
pWJ89alt contains GFP controlled by the promoter J23117alt, which can be activated by dCas9-w bound to sgRNA X4 and inhibited by dCas9-w bound to sgRNA X0 or X35.
Materials and method
- Phusion and Q5 PCR (cf. Protocols) pWJ89 wihtout its J23117 promoter with primers f_Rmv_J23117_of_pWJ89 and r_Rmv_J23117_of_pWJ89 + agarose gel electrophoresis of 2 µL PCR products (with 1kb Generuler) + PCR product purification (cf. Protocols). pWJ89 was a gift from David Bikard.
- Phusion and Q5 PCR J23117alt promoter with primers f_G_J23117Alt1IDT and r_G_J23117Alt1IDT + agarose gel electrophoresis of 2 µL PCR products (with 1kb Generuler) + PCR product purification (cf. Protocols). J23117alt was synthesized by IDT.
- Gibson assembly of pWJ89alt with purified PCR products pWJ89 (without J23117) and J23117alt promoter + transformation (cf. Protocols) of ultra-competent DH5a cells (NEB)Control with colony PCR (cf. Protocols) with primers f_Cl_pWJ89 and r_Sq_J23117alt primers + agarose gel electrophoresis of 2 µL PCR prodcuts (with 1kb Generuler) + sequencing (Microsynth)
Results
PCR pWJ8905.08.2015
Successful PCR reactions are expected to yield 4400 bp amplicons.Both negative control lanes (cf. Fig.14) are empty, which means there is no contamination. Phusion PCR did not work, but Q5 PCR did (cf. Fig.13). We will work with this sample for next steps.
PCR J23117alt promoter05.08.2015
Successful PCR reactions are expected to yield 340 bp amplicons.Both negative control lanes (cf. Fig.14) are empty, which means there is no contamination. Both Phusion and Q5 PCR worked (cf. Fig.13). We will work with the sample amplified by Q5 PCR.
Gibson assembly of pWJ89altGibson assembly, transformation: 10.08.2015, Colony PCR: 11.08.2015
Colony PCR showed two colonies for which Gibson assembly worked. However, images of gels of colony PCR were lost for technical reasons.Sequencing confirmed that both colonies were in fact pWJ89alt and that one had a deletion but the other one did not have any mutations. We kept the mutation-free colony and stored it in a Glycerol stock (cf. Protocols).
Construction of pAraC-sgRNA25.08.2015 - 03.09.2015
We made 3 pAraC-sgRNA constructs: pAraC-Z0 and pAraC-Z4 contain sgRNA Z0 or Z4 producing cassettes controlled by promoter pBAD-AraC (positively regulated by arabinose) and pAraC-Z0-Z4 contains sgRNA Z0 producing cassette controlled by promoter pBAD-AraC and sgRNA Z4 producing cassette controlled by promoter pBAD (constitutively active).
Materials and method
- Linearize pAraC by Q5 PCR (cf. Protocols) with primers f_opn_pAraC and r_opn_pAraC + agarose gel electrophoresis of 2 µL PCR products (with 1kb Generuler) + PCR product purification (cf. Protocols). pAraC, called pFIF on Addgene, was a gift from Jay Keasling (Addgene plasmid #17565).
- Extract sgRNA from pdCas9-w-sgRNA by Q5 PCR (cf. Protocols) with primers as indicated in table below + agarose gel electrophoresis of 2 µL PCR products + PCR product purification (cf. Protocols)
- Gibson assembly of pAraC-sgRNA constructs with purified PCR products pAraC and sgRNA + transformation (cf. Protocols) of ultra-competent DH5a cells (NEB)Control with colony PCR (cf. Protocols) with primers f_Sqc2_CoP_pAraCsgRNAs_sg1 and r_CoP_pAraCsgRNAs primers + agarose gel electrophoresis of 2 µL PCR prodcuts (with 1kb Generuler) + sequencing (Microsynth)
Construct | sgRNA cassette(s) | Forward primer(s) / Reverse primer(s) |
---|---|---|
pAraC-Z0 | Z0 | f_Gbs_sgRNAinpAraC / r_Gbs_sgRNAinpAraC |
pAraC-Z4 | Z4 | f_Gbs_sgRNAinpAraC / r_Gbs_sgRNAinpAraC |
pAraC-Z0-Z4 | Z0Z4 | f_Gbs_sgRNAinpAraC / r_Gbs_sgRNAwoAraf_Gbs_sgRNAwoAra_VS / r_Gbs_sgRNAinpAraC |
Results
PCR pAraC and sgRNA25.08.2015, 26.08.2015
Successfully amplified PCR products should be 5612 bp for pAraC and ??bp for the sgRNAs. pAraC was successfully amplified and we will use sample #1 for the next steps (cf. Fig.16b). sgRNAs Z0 and Z4 were succefully amplified with different sets of primers, as indicated in table above (cf. Fig.16a).
Assemble pAraC-sgRNA constructsGibson assembly and transformation: 28.08.2015, 01.09.2015, Colony PCR: 31.08.2015, 02.09.2015
Colony PCR (pictures of gels were lost for technical reasons) and seqeuncing confirmed Gibson assembly was successful for one colony for each construct.
Construction of pWJ89alt_Z4-to-X418.08.2015 - 02.09.2015
pWJ89alt_Z4-to-X4 contains a cassette producing sgRNA X4 (activator for J23117alt) controlled by the promoter J23117 and GFP under the J23117alt promoter (corresponds to pWJ89alt).
Materials and method
- Open pWJ89alt by restriction digest with AfeI + Agarose gel electrophoresis of 2 µL of digested product (with 1kb Generuler)
- Amplify Z4-to-X4 by Q5 PCR (cf. Protocols) with primers f_Gb_pWJ89alt and r_Gb_pWJ89alt + agarose gel electrophoresis of 2 µL PCR products + PCR product purification (cf. Protocols)
- Gibson assembly of pWJ89alt_Z4-to-X4 with linearized pWJ89alt and purified PCR product of Z4-to-X4 + transformation (cf. Protocols) of ultra-competent DH5a cells (NEB)Control with colony PCR (cf. Protocols) with primers f_Cl_pWJ89 and r_Sqc_T2reporter + agarose gel electrophoresis of 2 µL PCR prodcuts + sequencing (Microsynth)
Results
Open pWJ89alt by restriction digest18.08.2015
Undigested pWJ89alt is expected to migrate faster than digested pWJ89alt. We observe both bands at the same height (cf. Fig.17). As there is a smear for the digested sample, it may have been paritally digested.
PCR Z4-to-X419.08.2015
Amplicons should be 425 bp. We did 4 samples with slightly different thermocylcing settings. All were successfully amplified (cf. Fig.18) and we kept sample in lane 1 for next steps.
Gibson assembly pWJ89alt_Z4-to-X4Gibson assembly and transformation: 28.08.2015, Colony PCR: 31.08.2015
Primer table
Name | Sequence | Associated part |
---|---|---|
f_Gbs_pdCas9 | CTCGAGTAAGGATCTCCAG | pdCas9 |
f_Gbs_sgRNA-CtoA | GTCGGCGATGGTGGTAGCTAATTATGTTCCctcgctcactgactcgctac | sgRNA cassettes |
f_Gbs_sgRNA-DtoA | CTAGACCTAACTGAGATACTGTCATAGACGctcgctcactgactcgctac | sgRNA cassettes |
f_Gbs_sgRNA-A | ctcgctcactgactcgctac | sgRNA cassettes | f_Gbs_w | ACACGCATTGATTTGAGTCA | pWJ66 |
f_Mt_A2080C_pdCas9-w | TGACTTTTCGcATTCCTTATTATGTTG | pdCas9-w |
r_Gbs_pdCas9 | GTCACCTCCTAGCTGACTC | pdCas9 |
r_Gbs_sgRNA-B | tggcatcttccaggaaatc | sgRNA cassettes/td> |
r_Gbs_sgRNA-BtoC | GGAACATAATTAGCTACCACCATCGCCGACtggcatcttccaggaaatc | sgRNA cassettes |
r_Gbs_sgRNA-BtoD | CGTCTATGACAGTATCTCAGTTAGGTCTAGtggcatcttccaggaaatc | sgRNA cassettes/td> |
r_Gbs_w | atttgatgcctggagatccttactcgagTTAACGACGACCTTCAGCA | pWJ66 |
r_Mt_A2080C_pdCas9-w | AGATTTTTTCAATCTTCTCACG | pdCas9-w |
r_Scq_pdCas9_w_sgRNA | ctgatttgagcgtcagat | pdCas9-w-sgRNA |