A major problem in patenting a gene is that, as a large informational molecule, its sequence can vary in nearly limitless ways. There are millions of possible alternative EPO sequences. But the question of patentability of gene variants remains fuzzy. But this is not comparable to DNA, where the consequences of changing a base are not always predictable. Genes as research tools Disease-causing genes are not the only types of DNA with utility.
Researchers use small pieces of DNA to map genes on chromosomes.
The biotechnology community is split on whether such short DNA sequences should be patentable. The rationale for the turnaround was that an EST itself has no specific function but is a research tool. Many ESTs are available to researchers from GenBank , a database at the National Center for Biotechnology Information , although some companies are still trying to patent newly discovered ESTs. More recently, the patenting debate has centered around SNPs, or single nucleotide polymorphisms. Several large pharmaceutical companies are collaborating with biotechnology companies to patent SNPs for use in gene discovery.