We report here a comparison of isotopic and non-isotopic conformation analysis approach, for screening genomic DNA for coding variations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. A large pool of non-human primates was tested in order to detect naturally occuring CFTR carriers, for future testing of gene therapy of cystic fibrosis. We screened 25 of 27 CFTR exons in over 1,000 animals. We have detected numerous missense mutations and single nucleotide polymorphisms. We found that both methods are highly efficient for detection of variations in DNA sequence, but the non-radioactive approach is faster, less expensive and in some cases more sensitive.