Making Glycerol Stocks
Note: only BL21(DE3)+M33S/M103S and BL21(DE3)+M8S/M33S/M103S colonies grew overnight
- For each culture:
- Add 250μL of sterile 60% glycerol to a sterile 1 mL CryoTube vials
- Add 750μL of the overnight growth to the vial
- Mix well by pipetting up and down
- Place the vial in a -80°C freezer for long term storage
Expressing the Triple Mutant
- Centrifuge the cultures grown overnight at 3500rpm at 4°C for 15 minutes.
- Resuspend each of the pellets in 1mL of LB broth.
- Add each of the resuspended pellets with broth to one of the four 2800mL flasks made and autoclaved yesterday with 1L of sterile LB.
- Add 1mL 100mg/mL ampicillin to each flask.
- 100mg/mL ampicillin prepared with 5mL of distilled water and 0.5g of ampicillin, mixed and sterile filtered.
- Add 1mL of 40mg/mL hemin in dimethylformamide to each of the flasks.
- 40mg/mL hemin: 160mg hemin + 4mL dimethylformamide, mixed
- Incubate these flasks at 37°C at 165rpm for about two hours.
- Add 1mL of 0.1M IPTG to each flask. Continue to incubate at 37°C at 165rpm for about three more hours.
- Centrifuge these cells at 4500rpm at 4°C for 15 minutes.
- Resuspend the pellets in 50mM Tris 50mM NaCl, pH ~9 (sterile-filtered).
- Place resuspended cells in -20°C freezer.
Running a DNA Gel of Yesterday's PCR Product
- Make a 1.2% agarose gel (0.3g agarose + 25mL TAE buffer, microwave until boiling, then pour into gel chamber, and place comb for wells)
- When the gel has solidified, add TAE buffer to the chamber until the gel is completely submerged in buffer
- Load 10μL of DNA ladder into the 1st well
- Load 10μL of the experimental PCR product from yesterday with 2μL 6x loading buffer into the 3rd well (mix before pipetting into well)
- Load 10μL of the control PCR product from yesterday with 2μL 6x loading buffer into the 5th well (mix before pipetting into well)
- Run the gel at 100V until the "dye line" has moved about 3/4 of the way down the gel
- Place the gel in Ethidium Bromide Stain for about 30 minutes
- Move the gel to TAE buffer to destain for about 20 minutes
- View under a UV light
- Be careful when working with ethidium bromide and UV light.
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No DNA showed up on the gel in the PCR product lane (Lane 3). Will try to transform anyways.
Making Ampicillin Stocks
- Mix 1g of ampicillin with 10mL dH2O
- Sterile filter this solution
- Aliquot 1mL each into microcentrifuge tubes
- Label and store at -20°C for future use
Transformations
Transformations of the Asc Hb mutations M33S, M33S/M103S, and M8S/M33S/M103S into NovaBlue E.coli will be done in order to make glycerol stocks tomorrow. The wild-type plamids for Asc Hb and myoglobin (wt swMb pT7-7) will also be transformed into NovaBlue in order for glycerol stocks to be made. Also, the PCR product from yesterday (Asc Hb M8S/M33S/M103S/A71M) will be transformed into NovaBlue to be mini-prepped in the future. The following procedure will be followed for all of these transformations:
- Take a sterile microcentrifuge tube and place it on ice.
- Mix 50μL of NovaBlue Competent E.coli with 5μL of plasmid or PCR product in the cold, sterile tube.
- Incubate this mixture for 30 minutes on ice.
- Transfer the tube to a heat block at 42°C for 90 seconds, and then transfer the tube back to ice for 5 minutes.
- Add 200μL of SOC media to the cells/plasmid or PCR product.
- Shake the mixture at 165rpm at 37°C for one hour.
- Spread 100μL of the mixture on an LB plate with 100μg/mL ampicillin.
- The LB plates were made with 5.25g LB, 4.2g Agar, and 210mL of distilled water. The mixture was autoclaved on a liquid cycle. When the mixture cooled to about 60°C 210μL of 100mg/mL ampicillin was added to it and it was poured approximately evenly into 6 sterile petri dishes.
- Incubate the plate overnight (inverted) at 37°C.
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