Dear All, we were wondering if knows of an Escherichia coli B strain that is Rec deficient (Rec-). We want to compare certain properties of E coli B and K12, and for the experiment it would be best to use a Rec- variant. We have TOP10, which is a K12 derivative that is Rec-, but derivatives of B like BL21 are Rec+. Have a happy Easter, Mark
Mark J van Raaij Lab 20B Dpto de Estructura de Macromoleculas Centro Nacional de Biotecnologia - CSIC c/Darwin 3 E-28049 Madrid, Spain tel. (+34) 91 585 4616 http://www.cnb.csic.es/~mjvanraaij
