Team:UNAM Genomics Mexico/Notebook/Protocols
From 2012.igem.org
Protocols
E. coli Protocols
PCR Protocol (50µl)Buffer Pfu 5 µl |
Hot start PCR protocolPreheated 105ºC |
LigationThese are done in 1 mL eppendorf tubes and normally have a T.V. of 20 µl. •Add A µl of the insert (plasmid digested with corresponding enzymes). |
Dephosphorylation protocol-It is done to plasmids digested with the corresponding enzymes that will serve as a “vector” in a ligation. |
Transformation•Pipette the plasmid to a 1.3 mL eppendorf with competent cells and mix with the pipette. |
Liquid culture•Once the bacteria has grown, add 4 mL LB broth to a glass tube. |
Digestion protocol (20 µl)H2O 9.5 µl |
Gel extraction protocol(Fermentas Gene Jet Gel extraction kit) |
Lysis protocol1. Cultivate strain of interest in 5 µl LB with antibiotics. |
Gel electrophoresis-Sample preparation -Gel preparation and loading |
Competent cells protocol•Grow cells in LB all night. |
BUFFERSTfbI: Mw-> 100ml TfbI:100ml
10mM MOPS or PIPES 209.27->0.20927 |
PCR purification•Add 500 μl solution I “green lid” from kit of PCR purification to eppendorf tube. |
GLYCEROL PROTOCOL•Add 500 μl glycerol at 70% to a 1.5 mL eppendorf tube. |
PLASMID EXTRACTION 2Once grown in liquid culture: |
Bacillus subtilis Protocols
Escherichia coli MC1061 competent cells protocol
1.Plate the cells on LB, incubate at 37°C overnight. |
Escherichia coli MC1061 heat shock transformation protocol
1.Add the DNA solution to the competent cells and let them 5-20 minutes on ice |
Two-step Bacillus subtilis Transformation ProcedurePreparation of Bacillus subtilis competent cell 2.The following morning wash the cell growth of the plate with 3 ml of Spc and add 3 drops of the solution to inoculate fresh, pre-warmed, SpC medium (30 ml) in a klett flask and measure to give an OD600 reading of about 0.5 using a green filter. 3.Incubate the culture at 37°C with vigorous aeration and take periodic OD readings (OD600) to assess cell growth. (measure every 15 minutes) 4.When the rate of cell growth is seen to depart from exponential (i.e. no significant change in cell density ~5% over 15 min), dilute cell culture 1:10; inoculate 300 ml of pre-warmed, SpII medium with 30 ml of stationary-phase culture and continue incubation at 37°C with slower aeration. 5.After 90 min incubation, pellet the cells by centrifugation (8,000 g, 10 min) at 4°C. 6.Carefully decant the supernatant into a sterile container and save. 7.Gently resuspend the cell pellet in 30 ml of the saved supernatant and add 3 ml of sterile glycerol to a 10% concentration; mix gently. 8.Aliquot the competent cell (0.35 ml) in sterile eppendorf tubes, freeze rapidly in liquid nitrogen bath and store -80°C. Transformation 1.Add one volume of SpII + EGTA to the competent cells; mix gently 2.Add the DNA solution (500 & 1000 ng) and incubate at 37°C for 1 hour at 200 rpm. 3.Plate 100 microliters immediately onto selective media. 4.Pellet the cells 1 min at 1200 rpm and resuspend in 100 microliters. 5.Plate onto selective media. NOTE: if you were not able to select you Bacillus, maybe it is because you kill them before they activate their resistance gene. So, made the 5th step different, plate but the 1/40 of the antibiotic, to active the gene and incubate for 1 hour. Then put soft-agar until the petri dish is cover and put the original amount of antibiotic. Leave them overnight (16-24 hours) to grow. Media for two-step trasformation procedure SpC Made fresh on the day of use from the following sterile solution: SpII Made fresh on the day of use from the following sterile solutions: SpII + EGTA SpII (200 ml) with 4 ml EGTA (0.1 M, pH 8.0) but without CaCl2. SpII + EGTA can be frozen at -20 in small ℃ aliquots, although repeated freeze-thawing should be avoided. |