• Protocol

• E. coli
• January
• March
• May
• June
• July
• August
• September

• L. casei
• August
• September

Protocol

Common

PCR (2 STEP)

2 Step Cycle (Tm value ≥ 63℃)

PCR (3 STEP)

3 Step Cycle (Tm value ≤ 63℃)

Digestion

Digestion

Sequencing

Sequencing

Ligation

Ligation

PCR Purification

FastGene^TM Gel/PCR Extraction kit (Nippon Genetics Co., Ltd)
Purification of PCR products

Dephosphorylation

Dephosphorylation

Electrophoresis

Gel Extract

FastGene^TM Gel/PCR Extraction kit (Nippon Genetics Co., Ltd)
DNA extraction from gel

Annealing of Oligonucleotides

Annealing of Oligonucleotides

E. coli

Liquid Culture

Culture for several hrs.

Mini-prep

FastGene^TM Plasmid mini kit (Nippon Genetics Co., Ltd)
fast / standard / low copy protocol

Colony PCR (2 STEP)

2 Step Cycle (Tm value ≥ 63℃)

Colony PCR

3 Step Cycle (Tm value ≤ 63℃)

Transformation (with pre-culture)

1. Add plasmid to thawed competent cells on ice.
2. Place it on ice for 30 min.
3. Heat-shocked for 30 sec at 42℃.
4. Add LB.
5. Incubate the cells for 2 hrs at 37℃.
6. Spread 300 µL of the culture onto plate with antibiotic.
7. Incubate the plate at 37℃.

Transformation (w/o pre-culture)

1. Add plasmid to thawed competent cells on ice.
2. Incubate on ice for 30 min.
3. Heat-shocked for 30 sec at 42℃.
4. Spread 300 µL of the culture onto plate with LBA.
5. Incubate the plate at 37℃.

Ethanol Precipitation

1. Add 1/10 volume of NaOAc, 1.5 µL of glycogen and 5/2 volume of 100% ethanol.
2. Leave it at -80℃ for 1 hr.
3. Centrifuge at 15,000 rpm for 15 min at 4℃.
4. Remove supernatant and add 220 µL of 70% ethanol.
5. Centrifuge at 15,000 rpm for 10 min at 4℃.
6. Remove supernatant and air-dry at room temperature with light shield.
7. Suspend with 10 µL of DW.

Streaking (Single Colony Isolation)

1. Pick the colony with an inoculating loop from the agar plate．
2. Drag the loop across on a new agar plate.
3. Re-sterilise the loop and drag it across again.

Competent Cells

1. Thaw original competent cells on ice.
2. Add 5 µL of original competent cells to 2 mL of LB.
3. Incubate the cells for 16 hrs at 37℃.
4. Add 5 µL, 50 µL, and 500 µL of original cells to 100 mL of LB.
5. Incubate the cells at 130 rpm at 20℃, until OD₆₀₀ reach 0.5.
6. Take 50 mL of incubated cells to two differnt culture tubes and centrifuge them at 3,000 rpm for 20 min at 4℃.
7. Remove supernatant and add 75 mL of TB to each tube.
8. Bring them to a one tube and centrifuge at 3,000 rpm for 20 min at 4℃.
9. Remove supernatant and add 32 mL of TB.
10. Add 32 µL of DMSO 10 times.
11. Take 50 µL and freeze with liquid nitrogen.

L. casei

Preparation of Bacteria

1. Added 5 mL of L. casei to MRS medium.
2. Cultured overnight.
3. Measured OD₆₀₀ and diluted with MRS medium to set OD₆₀₀ to 0.2.
4. Stand cultured for 1.5 ~ 2 hrs until OD₆₀₀ is 0.4 ~ 0.5.
5. Incubated the cells on ice for 10 min.
6. Centrifuged at 6,000 g for 15 min at 4℃.
7. Removed supernatant and added 30 mL of cooled PEB.
8. Centrifuged at 6,000 g for 15 min at 4℃.
9. Removed supernatant and added 30 mL of cooled PEB.
10. Centrifuged at 6,000 g for 15 min at 4℃.
11. Removed supernatant and added 1 mL of cooled PEB.

Electroporation

1. Prepared the plasmid to 300 ng/10 µL (TE pH 8).
2. Mixed 10 µL of plasmid and 200 µL of bacteria and incubated on ice for 10 min.
3. Electoroporated at 2 kV with Gene Pulser (Bio-Rad) and Gene Pulser®/MicroPulser^TM Electroporation Cuvettes(0.2 cm gap #1652086).
4. Added 800 µL of cooled MRS medium and stand cultured for 3 hrs in 30℃.
5. Spread on MRS plate (Em 5 µg/mL).

Buffer

PEB Buffer

Filtrate with 0.22 µm filter.

0.1 M Phosphate Buffer

Mix 0.1 M NaH₂PO₄ and 0.1 M Na₂HPO₄ and prepare it to pH 7.3..
Autoclave for 20 min at 121℃.

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