Team:UCLA/Notebook/Honeybee Silk/21 July 2015
Inoculation of 7/20 Transformtion
Lots of colonies were present, 6 colonies were picked and inoculated with 5 mL LB broth and 5uL 1000X kanamycin.
Inclusion Body Purification of Honeybee Protein
- Determine wet wet weight of cell pellet after spinning liquid culter at 10000 x g for 10 min.
- 1.25 g
- Resuspend in 5 ml/g Bug Buster (1x) by pipetting and gently vortexing.
- This is 6.25 ml in our case
- Put on shaker or rotating mixer for 15 min at RT
- Took our first fraction at this point of the full cell lysate (F1)
- Centrifuge 16000 g 20 min at 4 degrees C
- Took next fraction at this point of the supernatant, labeled (S1)
- Resuspend pellet in same volume of 1X bugbuster as before
- 6.25 ml
- Pipette up and down and vortex gently to get an even suspension.
- Took third fraction at this point (F2)
- I did not go to great lengths to get an even suspension here, but I noticed in retrospect that the protocol emphasized the importance of this in order to get pure inclusion bodies.
- Add dry lysozyme to final concentration of 200 ug / ml
- For 6.25 ml solution I added around 1.25 mg of lysozyme
- Added 1 ul of DNAse to remove chromosomal DNA.
- Add 6 volumes of 1:10 diluted bugbuster (.1X)
- At this point we split the solution up into two 50 ml falcon tubes and added 18.75 ml of .1X bugbuster to each tube
- Centrifuge 16000g 15 min. 4 degrees C to collect inclusion bodies.
- Remove supernatant w/ pipette, take next fraction (S3)
- After spinning this down, there was a pellet, with chromosomal DNA.
- It was difficult to remove the supernatant because the viscous liquid kept getting sucked up and bringing the pellet up with it.
- Resuspend pellet in 1/2 volume of original 0.1X bug buster solution
- 9.375 ml per tube
- Mix to get an even suspension by pipetting and vortexing for several minutes and spin down as in step 9.
- Repeat was two more times.
- Take samples of supernatant at each wash step
- Resuspend inclusion body pellet in 3% SDS solution and incubate at 60 C in the water bath for 2 hours
- I used around 2 ml, but I probably could have used less, because the pellet dissolves well in the heat
- Store solution at 4C until further required.
- I noticed that after a day in the 4C, the solution gelled up.
- According to protocol, storage at temperatures below 4°C may cause precipitation of the detergents in BugBuster reagent. Incubate in a room temperature water bath with gentle swirling to redissolve.