Ultrasensitive assays for endogenous antimicrobial polypeptides.
We developed two sensitive methods for identifying antimicrobial molecules in leukocytes and other tissues. One method uses a gel overlay technique and was designed to identify antimicrobial polypeptides in samples subjected to polyacrylamide gel electrophoresis. The other, a radial diffusion assay, allows multiple fractions obtained by chromatographic procedures to be tested for antimicrobial activity conveniently. When we used E. coli ML-35p or Salmonella typhimurium 14028S as test organisms in the radial diffusion assay, we routinely detected 5-10 ng of rabbit defensin NP-1 in 5 microliters of sample. With minor modifications, both methods can be applied to other organisms, including Gram-positive bacteria, several Candida species and Cryptococcus neoformans.
Lehrer
R I
RI
Department of Medicine, UCLA Center for the Health Sciences 90024.
Rosenman
M
M
Harwig
S S
SS
Jackson
R
R
Eisenhauer
P
P
D000818:Animals; D001770:Blood Bactericidal Activity; D001798:Blood Proteins / Q000032:analysis* / Q000494:pharmacology; D015169:Colony Count, Microbial; D023082:Defensins; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D004926:Escherichia coli / Q000254:growth & development; D006801:Humans; D005779:Immunodiffusion / Q000379:methods; D009504:Neutrophils / Q000276:immunology*; D011817:Rabbits; D012486:Salmonella typhimurium / Q000254:growth & development
D001798:Blood Proteins; D023082:Defensins