After two years and more than 1,000 tissue homogenates, we are beginning to quantitate our computer database of profile information in order to further augment our genetic quality assurance program. We can now supplement raw data with sophisticated densitometry of our autoradiograms and gels. Though we are still using biochemical isozymes to routinely check the genetic authenticity of rodents used as experimental models both within and outside NIH, we now regularly supplement these assays with DNA fingerprinting. We have found the technique absolutely essential in testing for genetic purity in both recombinant and congenic strains. It is perhaps the only reliable way to distinguish between certain species of rodents.
