Reducing the artifacts produced by impure antisera in immunoblots of low-molecular-mass proteins in urine.
Abstract Immunoblots of several urinary low-molecular-mass proteins can be very useful in investigations of pathological proteinuria. However, use of certain commercial antisera in such procedures leads to artifacts corresponding to nonspecific bands; e.g., immunoglobulins from nonimmunized rabbit serum may bind to human urinary proteins, and this binding is not inhibited by Triton X-100. We have developed a procedure to improve the specificity of detection of urinary low-Mr proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, by immunoblotting with commercial antisera: we treat the protein blot with a mixture of mercaptoethanol and sodium dodecyl sulfate before incubation with the first antiserum. This allows direct use of commercial antisera without prior absorption of contaminating antibodies.
Catalytic activities of human poly(ADP-ribose) polymerase from normal and mutagenized cells detected after sodium dodecyl sulfate-polyacrylamide gel electrophoresis.