Product Class: Strain

E. coli K12 KS1000

Limit of 1 per order. Although this product is free of charge, freight charges will apply. For US customers, available via phone ordering only (1-800-632-5227). For international customers, please contact your local NEB subsidiary or distributor.
Catalog #SizeConcentration


A suspension of E. coli K12 KS1000 which has been grown in M63 or M9 minimal glucose medium and brought to 50% glycerol. This strain is deficient in the Prc protease, a periplasmic protease (formerly known as Tsp, tail-specific protease). The Prc protease can degrade cytoplasmically expressed proteins when the cells are lysed to make a crude extract, and presumably it can degrade proteins expressed in the periplasm as well.


F' lacIq lac+ pro+/ ara Δ(lac-pro) Δ(tsp)= Δ(prc)::KanR eda51::Tn10(TetR) gyrA(NalR) rpoB thi-1 argE(am)

Properties and Usage

Storage Temperature


Supporting Documents

The following is a list of Safety Data Sheet (SDS) that apply to this product to help you use it safely.


  1. KS1000 is EcoK r+m+, so plasmids have to be modified (i.e., come from an m+ strain such as TB1, JM83, JM107, etc.) in order to get transformants.


  1. Silber, K.R., Keiler, K.C. and Sauer, R.T. (1992). Proc. Natl. Acad. Sci. USA. 89, 295-299.
  1. When we analyze our fusion protein expression by Western blot using the Anti-MBP Monoclonal Antibody, only a small fraction of the protein is full-length, while most of it migrates close to the MBP5* marker.