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| <br /><br /> | | <br /><br /> |
| <b>Chemically Competent Transformation</b> | | <b>Chemically Competent Transformation</b> |
- | <br />Materials | + | <br />Materials: |
| <br />1 aliquot of competent cells | | <br />1 aliquot of competent cells |
| <br />2-4μl ligation mixture | | <br />2-4μl ligation mixture |
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| <br /><br />Procedure | | <br /><br />Procedure |
| <br />Thaw cells at 4°C for 5 minutes | | <br />Thaw cells at 4°C for 5 minutes |
- | Gently mix in ligation product | + | <br />Gently mix in ligation product |
- | Incubate at 4°C for 20 min | + | <br />Incubate at 4°C for 20 min |
- | Meanwhile, warm SOC media to 37C | + | <br />Meanwhile, warm SOC media to 37°C |
- | Heat shock at 42°C for 30 sec | + | <br />Heat shock at 42°C for 30 sec (45 sec for NEB5-alpha cells) |
- | 45 sec for NEB5-alpha cells | + | <br />Return to 4°C for 1 min |
- | Return to 4°C for 1 min | + | <br />Add 500μl pre-heated SOC |
- | Add 500μl pre-heated SOC | + | <br />Incubate at 37°C for 1hr with shaking |
- | Incubate at 37°C for 1hr with shaking | + | <br />Meanwhile, pre-heat plates to 37°C |
- | Meanwhile, pre-heat plates to 37°C | + | <br />Plate, one plate w/ 100μl, one plate w/ 150μl |
- | Plate, one plate w/ 100μl, one plate w/ 150μl | + | |
| | | |
- | <br /><br />Electrocompetent Cells | + | <br /><br /><b>Acetobacter Transformation (electroporation)</b> |
- | <br />Alex is a fan of electroporation because it’s faster and more efficient than the chemical protocol. The only downside is that it’s incompatible with the NEB Instant Ligase mixes. | + | <br /> |
- | We got good results from these protocols.
| + | |
- | | + | |
- | <br /><br />Preparing Electrocompetent Cells | + | |
- | Prepare a 10ml pre-culture on LB medium. For best results, avoid using overnight preculture.
| + | |
- | Dilute pre-culture as follows: 4 ml in 200-ml of fresh LB pre-warmed at 37°C.
| + | |
- | Grow the cells at 37°C.
| + | |
- | When OD (600) = 0.6 is reached, chill the culture on ice as quickly as possible.
| + | |
- | Centrifuge in disposable tubes (50ml disposable type) for 5 minutes at 3000 rpm.
| + | |
- | Resuspend the pellets in 25ml freshly prepared water¹ (MilliQ®quality) at ice temp.
| + | |
- | Repeat steps 5 & 6 twice more.
| + | |
- | Resuspend the pooled pellets in 400µl (cell concentration should be 1 x 1010 cells x ml−¹) freshly prepared water (MilliQ® quality) at ice temp.
| + | |
- | Check the final volume and add 10% of glycerol (molecular biology grade).
| + | |
- | Use immediately or aliquot the electrocompetent cells to 100µl in 10% glycerol and freeze at - 70°.
| + | |
- | Transforming Electrocompetent Cells
| + | |
- | Defrost an aliquot of electrocompetent cells
| + | |
- | Load an Eppendorf tube chilled on ice with 40µl of cell suspension
| + | |
- | Add 1 to 5µl of ligation mix (DNA)
| + | |
- | Mix well and keep on ice for >1 minute
| + | |
- | Select 1800 Volt as the output voltage (for 1mm cuvettes, for 2mm use 2500)
| + | |
- | Load an electroporation cuvette chilled on ice with the cell suspension
| + | |
- | Avoid putting your finger on the aluminium electrodes or it will dramatically increase the temperature of the sample and increase the risk of arcing
| + | |
- | Trigger the pulse immediately
| + | |
- | As soon as possible (less than 30 seconds) resuspend the cells in the cuvette with 1ml SOC medium (the quality of the SOC is important)
| + | |
- | Transfer the cells in an appropriate vessel and incubate at 37°C for 1 hour (30 minutes is usually enough)
| + | |
- | 250 rpm shaker is best
| + | |
- | Plate the cells on the selective medium. 100uL and 300uL are good starting amounts.
| + | |
- | Incubate overnight and look for transformant colonies in the morning
| + | |
| | | |
| <br /><br />PAGE Gel Preparation, Running, and Scanning (proteins only) | | <br /><br />PAGE Gel Preparation, Running, and Scanning (proteins only) |
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| Doubling time for E.coli in ideal conditions, 37ºC = 20 minutes | | Doubling time for E.coli in ideal conditions, 37ºC = 20 minutes |
| | | |
- | <br /><br />Media recipes | + | <br /><br /><b>Site Directed Mutagenesis</b> |
- | <br />LB
| + | |
- | <br />10 g tryptone | + | |
- | <br />5 g yeast extract
| + | |
- | <br />10g NaCl
| + | |
- | <br />Autoclave for 20 minutes
| + | |
- | <br /><br />To make LB agar, add 15 g agar or bacto-agar prior to autoclaving (makes ~ 25)
| + | |
- | | + | |
- | <br /><br />M9 media (minimal media useful for fluorescent measurements as LB is autofluorescent) NOTE: if not growing in M9 but just measuring fluorescence, M9 salts is sufficient.
| + | |
- | <br />Autoclave ingredients as 10X-100X stock separately prior to mixing in sterile water
| + | |
- | <br />1X M9 salt
| + | |
- | <br />2 mM MgSO4
| + | |
- | <br />0.1mM CaCl2
| + | |
- | <br />0.4% - 2% carbon source (glucose, glycerol, etc)
| + | |
- | <br /><br />To make M9 Agar, add 15g agar or bacto-agar to 1 L M9 salts prior to autoclaving, then add other ingredients (makes ~25 plates).
| + | |
- | | + | |
- | <br /><br />Antibiotic selection - Make stocks in sterile water, add to warm autoclaved media. Do not autoclave, as it will degrade the antibiotic.
| + | |
- | <br />Ampicilllin - 100 ug/mL, 100mg/mL 1000X stock
| + | |
- | <br />Kanamycin - 30 - 50 ug/mL, 30 mg/mL 1000X stock
| + | |
- | <br />Chloramphenical - 20 ug/mL 20mg/mL 1000X stock in ethanol
| + | |
- | <br />Streptomycin - 100 ug/mL
| + | |
- | | + | |
- | <br /><br />Storage - add 50% glycerol to stationary phase culture for final concentration of 15-25% glycerol, freeze at -80ºC.
| + | |
- | <br /><br />
| + | |
- | | + | |
- | <br /><br />Site Directed Mutagenesis
| + | |
| <br /><br /> | | <br /><br /> |
| 1. How to make primers (http://openwetware.org/wiki/Richard_Lab:Site_Directed_Mutagenesis) | | 1. How to make primers (http://openwetware.org/wiki/Richard_Lab:Site_Directed_Mutagenesis) |