SINGLE STEP EAZY COMPETENT CELL PREPARATION KIT , 50ml. Available 25ml package. Storage: All contents of the kit should be kept in freezer after usage. The Kit is stable for 9 months. This Kit contains SSCS solution, enables researchers to prepare competent E. coli cells in a single step and to transform the cells without heat-shock. SSCS has been reported to be faster and easier than other methods of producing competent cells, such as the traditional CaCl2 method described by Sambrook et al, or other high competency protocols. The competent cells obtained by this method can be kept at -70OC for long term storage. Transformation efficiencies depend on the strain of E. coli, as well as the nature and quality of the trasforming DNA. A typical transformation efficiencies is 106~108 transformants/ug DNA. For example, the transformation efficiencies observed for E. coli strains DH1, DH5a, HB101, JM109, LE392, MM294, SCS-1, XL1-blue and TG1 is about 108 per ug of DNA. Applications Preparation of E. coli competent cells for transformation. Features: Simple & Fast. Entire procedure takes about 5 minutes.Quality Control Transformation & Storage solution is tested for transformation efficiency with appropriate E. coli strains and pUC18 or pUC19 DNA. Protocol for Preparation of Competent Cells and Transformation 1. Add 1ml of cells at A600nm = 0.5~0.7 in 1.5ml microtubes. 2. Spin at 4000rpm for 4~5 min and then remove the supernatant. 3. Add 100ul of pre-cold SSCS and gently mix the cells. Aliquot cell mixture. It is ready to use or can be stored at -70OC for future use. 4. Add 100pg to 10ng of transforming DNA to the cells. 5. Mix the cells and DNA and place on ice for 10 min, then 37OC for 5 min, then on ice for 10 min. 6. Add 1ml of LB and incubate the tubes at 37 OC for 1 hour. 7. Plate the cells on the appropriate selective or differential media. Note: 1. For large volume of cell preparation, the volume of SSCS used should be scaled up. For example, 1~2ml SSCS solution can be used for 50~100 ml cultured cells. After the cells resuspend, aliquot of 50~100ul .The cells l should be dispensed and then stored at -70 OC. 2. This solution can work well with Bacillus subtilis, too.