Competent Cells

Competent bacterial cells for chemical or electroporation-based transformation and cloning

Chemically or electroporation-competent bacterial cells for transformation with plasmids, ligation reactions, BAC, or large constructs. The category includes standard cloning strains (DH5-alpha, JM109, TOP10), high-efficiency strains (Stbl3, Stbl4, NEB Stable for unstable repeats), expression strains (BL21(DE3), Rosetta, Lemo21 for difficult proteins), and specialty strains.

Pick by transformation efficiency and end use.

1. Efficiency. 10^8 to 10^10 cfu/microgram. Higher for ligation products and large constructs.
2. Strain genotype. recA mutations stabilise repeats. endA mutations improve plasmid yield. lacI for IPTG-inducible expression. T7 RNA polymerase for pET expression.
3. End application. Cloning, expression, recombineering, library construction each match specific strains.
4. Method. Chemical for routine. Electroporation for higher efficiency and large constructs.
5. Library construction. For libraries above 10^7 diversity choose electrocompetent with documented efficiency.

Lucigen leads on high-efficiency cloning strains including Stbl3 and Endura for unstable inserts. Antibody Design Labs covers expression and phage display strains.