: Along the same line, while I believe that the lower-case "m" in : mRNA means "messenger" and the lower-case "r" in rBST means : "recombinant", I am at a loss to figure out what the "c" in : cDNA means. It stands for Complimentary. The DNA is complementary to mRNA, and thus has had its introns removed in RNA Processing. -SG-