Aminichiello (Talk | contribs) |
Aminichiello (Talk | contribs) |
||
Line 114: | Line 114: | ||
</div> | </div> | ||
+ | <button class="accordion">Making Competent Cells</button> | ||
+ | <div class="panel"> | ||
+ | <p><ol> | ||
+ | <li> Using a sterile plastic loop, pick 10-12 large (2-3mm in diameter) colonies from the plate. Inoculate to 150mL of SOB medium in a 1L flask, and grow overnight at 18-22°C, 200-250rpm. Alternatively, set up a starter culture (2ml) overnight and inoculate the large scale in the morning. Grow at 37°C. </li> | ||
+ | <li> A600 should be 0.2-0.8 when harvest. Preferably, cells should be in mid log phase with A600 ~ 0.5 </li> | ||
+ | |||
+ | <li> Remove the flask from the incubator and place on ice for 10 minutes. FROM THIS STEP, KEEP THE CELLS ON ICE AS MUCH AS POSSIBLE!</li> | ||
+ | |||
+ | <li> Transfer the culture to a 15mL centrifuge tube and spin at 2500 x g for 10 min at 4°C</li> | ||
+ | |||
+ | <li> Pour off and discard the supernatant, and immediately place the tube on ice.</li> | ||
+ | |||
+ | <li> Resuspend your cells in 1mL of ice-cold TB buffer, make sure there are no clumps of cells left, but also treat your cells gently and keep them cold.</li> | ||
+ | |||
+ | <li> Add ice-cold TB buffer to bring volume up to 1/5th of the original culture volume (~30mL in this case). Mix the tube by gently inverting 3 times.</li> | ||
+ | |||
+ | <li> Incubate the tube on ice for 10 minutes.</li> | ||
+ | |||
+ | <li> Centrifuge at 2,500 x g for 7 minutes at 4°C, discard the supernatant.</li> | ||
+ | |||
+ | <li> Gently resuspend the cells in ~1/20th of the original culture volume of ice-cold TB buffer. NOTE: 1/20th is based on and OD600 of 0.5, so adjust volume accordingly. E.g. if the culture OD600 was 0.1 then resuspend in 1/100th of original volume.</li> | ||
+ | |||
+ | <li> Pre-chill 1.5ml Eppendorf tubes on ice. Add 930µl of your cell suspension, keeping the remainder on ice in the 15mL tube.</li> | ||
+ | |||
+ | <li> Add 70µl of DMSO to the 930µl of cell suspension. Mix gently by swirling, and place on ice. </li> | ||
+ | |||
+ | <li> Aliquot 100µl of the competent cell/DMSO mixture into fresh microcentrifuge tubes. Label the tubes with: Date – Strain. Snap freeze with liquid nitrogen or dry ice. Store cells at -80°C. </li> | ||
+ | |||
+ | |||
+ | </ol></p> | ||
+ | </div> | ||
Revision as of 09:23, 14 October 2017
|
Dry Lab
|
|
Dry Lab
|
|
Wet Lab
|
- Using a sterile plastic loop, pick 10-12 large (2-3mm in diameter) colonies from the plate. Inoculate to 150mL of SOB medium in a 1L flask, and grow overnight at 18-22°C, 200-250rpm. Alternatively, set up a starter culture (2ml) overnight and inoculate the large scale in the morning. Grow at 37°C.
- A600 should be 0.2-0.8 when harvest. Preferably, cells should be in mid log phase with A600 ~ 0.5
- Remove the flask from the incubator and place on ice for 10 minutes. FROM THIS STEP, KEEP THE CELLS ON ICE AS MUCH AS POSSIBLE!
- Transfer the culture to a 15mL centrifuge tube and spin at 2500 x g for 10 min at 4°C
- Pour off and discard the supernatant, and immediately place the tube on ice.
- Resuspend your cells in 1mL of ice-cold TB buffer, make sure there are no clumps of cells left, but also treat your cells gently and keep them cold.
- Add ice-cold TB buffer to bring volume up to 1/5th of the original culture volume (~30mL in this case). Mix the tube by gently inverting 3 times.
- Incubate the tube on ice for 10 minutes.
- Centrifuge at 2,500 x g for 7 minutes at 4°C, discard the supernatant.
- Gently resuspend the cells in ~1/20th of the original culture volume of ice-cold TB buffer. NOTE: 1/20th is based on and OD600 of 0.5, so adjust volume accordingly. E.g. if the culture OD600 was 0.1 then resuspend in 1/100th of original volume.
- Pre-chill 1.5ml Eppendorf tubes on ice. Add 930µl of your cell suspension, keeping the remainder on ice in the 15mL tube.
- Add 70µl of DMSO to the 930µl of cell suspension. Mix gently by swirling, and place on ice.
- Aliquot 100µl of the competent cell/DMSO mixture into fresh microcentrifuge tubes. Label the tubes with: Date – Strain. Snap freeze with liquid nitrogen or dry ice. Store cells at -80°C.