Ctsb^tm1Jde

A neomycin selection cassette was inserted into a BglII site in exon 4. Northern blot analysis of total RNA showed a lack of transcript in homozygous mutant mice. An absence of protein in homozygous mutant mice was determined by Western blot analysis of kidney lysosomal protein extracts. The proteolytic activity of the endogenous protein was found to be absent using an assay involving liver lysosomal extracts obtained from of homozygous mutant mice and a fluorogenic substrate. (J:64872)