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Strain instructions
Strain name: JM109(DE3) Escherichia coli Escherichia coli JM109(DE3)
Storage conditions: 2-8 ℃
Validity : 6 years
No. 341823
Product format: freeze dried, 200ul
Biosafety level: 1 , handle in ultra-clean table or safety cabinet
Uses: competent cells, plasmids, genetic engineering
Receiving notice: if any abnormality is found on the day of receipt, please contact the customer service within 24 hours. Please store at 2-8℃. The freeze dried culture shall be used up once and shall not be retained. Please operate in strict accordance with this instruction, otherwise the replacement of bacteria are not be available in case of aberrant growth and loss of viability.
Medium:LB agar medium yeast extract 5.0g, peptone 10.0g,NaCl 10.0g, agar 15.0g, distilled water 1.0 L,pH 7.0. Sterilization at 121 ℃ for 15min.
Growth conditions
Temperature :37 ℃
Gas environment : Aerobic
How to use A. Recovery 1. Prepare 2 LB plates; 2. under sterile conditions, draw 0.5mL of liquid culture medium into a lyophilized tube to fully dissolve the freeze dried pellets; 3.inoculate two plates with the liquid suspension, and streak the two plates, in 18-24h a single colony grow ; B. Competent preparation (for reference) 1. inoculate a test tube of 3ml LB liquid medium with a single colony from JM109(DE3) E. coli plate , and put the test tube on a shaker at 37 ℃ overnight. 2. take 1ml of bacterial solution and transfer it to a conical flask containing 50ml LB liquid culture medium. shake culture at 37 ℃ for 2~3h, A600 should be between 0.4~0.5, and the number of cells must be <108CFU/ml. 3. transfer 1ml of bacterial liquid to a 1.5 ml centrifuge tube with a pipette and place it on ice for 10min. 4. Centrifugation for 10min,4000r /min. 5. suck out all the supernatant and add 200ul of ice-cold CaCl ( 0.1mol/l), then immediately place on ice for 30min. 6. low temperature centrifugation for 10min,4000r /min to collect cells. 7. suspend the cells with 200ul of ice-cold CaCl ( 0.1mol/l). 8. sub-package cells, each 200ul, this is competent cells.