Strain AVB99 is a K12 E. coli strain (genotype: recA1 endA1 gyrA96 thi-1 hsdR17 supE44 relA1) containing pBirAcm, an engineered pACYC184 plasmid with an IPTG inducible birA gene to over-express the biotin ligase. The endA1 nuclease deficient strain is recommended for isolation of the pBirAcm plasmid that can be used to transform other E. coli strains to a biotin ligase over-expressing strains. The pBirAcm plasmid should be maintained and selected with chloramphenicol at 10 μg/ml concentration. This is a low copy number plasmid. Avidity, LLC provides glycerol stocks (AVB99) Quantity: 1 vial, containing 0.5 ml of bacterial glycerol stock. This product is shipped on dry ice and has to be stored at -80°C.