Team:StanfordBrownSpelman/Lab

From 2014.igem.org

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<b>Chemically Competent Transformation</b>
<b>Chemically Competent Transformation</b>
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<br />Materials
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<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
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Gently mix in ligation product
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<br />Gently mix in ligation product
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Incubate at 4°C for 20 min
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<br />Incubate at 4°C for 20 min
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Meanwhile, warm SOC media to 37C
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<br />Meanwhile, warm SOC media to 37°C
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Heat shock at 42°C for 30 sec
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<br />Heat shock at 42°C for 30 sec (45 sec for NEB5-alpha cells)
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45 sec for NEB5-alpha cells
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<br />Return to 4°C for 1 min
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Return to 4°C for 1 min
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<br />Add 500μl pre-heated SOC
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Add 500μl pre-heated SOC
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<br />Incubate at 37°C for 1hr with shaking
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Incubate at 37°C for 1hr with shaking
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<br />Meanwhile, pre-heat plates to 37°C
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Meanwhile, pre-heat plates to 37°C
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<br />Plate, one plate w/ 100μl, one plate w/ 150μl
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Plate, one plate w/ 100μl, one plate w/ 150μl
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<br /><br />Electrocompetent Cells
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<br /><br /><b>Acetobacter Transformation (electroporation)</b>
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<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.
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We got good results from these protocols.
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<br /><br />Preparing Electrocompetent Cells
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Prepare a 10ml pre-culture on LB medium. For best results, avoid using overnight preculture.
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Dilute pre-culture as follows: 4 ml in 200-ml of fresh LB pre-warmed at 37°C.
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Grow the cells at 37°C.
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When OD (600) = 0.6 is reached, chill the culture on ice as quickly as possible.
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Centrifuge in disposable tubes (50ml disposable type) for 5 minutes at 3000 rpm.
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Resuspend the pellets in 25ml freshly prepared water¹ (MilliQ®quality) at ice temp.
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Repeat steps 5 & 6 twice more.
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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.
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Check the final volume and add 10% of glycerol (molecular biology grade).
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Use immediately or aliquot the electrocompetent cells to 100µl in 10% glycerol and freeze at - 70°.
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Transforming Electrocompetent Cells
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Defrost an aliquot of electrocompetent cells
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Load an Eppendorf tube chilled on ice with 40µl of cell suspension
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Add 1 to 5µl of ligation mix (DNA)
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Mix well and keep on ice for >1 minute
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Select 1800 Volt as the output voltage (for 1mm cuvettes, for 2mm use 2500)
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Load an electroporation cuvette chilled on ice with the cell suspension
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Avoid putting your finger on the aluminium electrodes or it will dramatically increase the temperature of the sample and increase the risk of arcing
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Trigger the pulse immediately
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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)
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Transfer the cells in an appropriate vessel and incubate at 37°C for 1 hour (30 minutes is usually enough)
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250 rpm shaker is best
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Plate the cells on the selective medium. 100uL and 300uL are good starting amounts.
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Incubate overnight and look for transformant colonies in the morning
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<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
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<br /><br />Media recipes
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<br /><br /><b>Site Directed Mutagenesis</b>
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    <br />LB
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<br />10 g tryptone
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<br />5 g yeast extract
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<br />10g NaCl
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<br />Autoclave for 20 minutes
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<br /><br />To make LB agar, add 15 g agar or bacto-agar prior to autoclaving (makes ~ 25)
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<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.
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<br />Autoclave ingredients as 10X-100X stock separately prior to mixing in sterile water
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<br />1X M9 salt
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<br />2 mM MgSO4
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<br />0.1mM CaCl2
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<br />0.4% - 2% carbon source (glucose, glycerol, etc)
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<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).
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<br /><br />Antibiotic selection - Make stocks in sterile water, add to warm autoclaved media. Do not autoclave, as it will degrade the antibiotic.
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<br />Ampicilllin - 100 ug/mL, 100mg/mL 1000X stock
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<br />Kanamycin - 30 - 50 ug/mL, 30 mg/mL 1000X stock
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<br />Chloramphenical - 20 ug/mL 20mg/mL 1000X stock in ethanol
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<br />Streptomycin - 100 ug/mL
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<br /><br />Storage - add 50% glycerol to stationary phase culture for final concentration of 15-25% glycerol, freeze at -80ºC.
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<br /><br />Site Directed Mutagenesis
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<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)

Revision as of 01:24, 16 October 2014

Stanford–Brown–Spelman iGEM 2014 — Human Practices