Use of elastase as an internal standard in immunoblotting techniques

A non-radioactive method for relative, semi-quantitative analysis of immunoblots, based on the use of elastase as internal standard and conventional peroxidase staining was devised and applied to the immunoassay of Gs-proteins in crude membrane preparations of rat kidneys. We found that the coefficients of variation of samples, run within the same experiment or run within different experiments, are reduced to half or a quarter of their original value respectively when corrected for elastase as an internal standard, allowing meaningful comparison of these samples.