Although they've been in use for nearly a decade, deoxyribonucleic acid (DNA) probes are now becoming a research tool with seemingly endless applications for medicine. Among their uses are prenatal diagnosis, detection of pathogens, and diagnosis and typing of viral infections.
Referring to their ability to identify one molecule from hundreds of thousands of messenger ribonucleic acid (RNA) strands, one investigator has called the use of DNA probes "the magnet to pull the needle out of the haystack."
DNA probes are specific, single-stranded nucleic acid sequences that are used to search for complementary sequences from a pool of single-stranded DNA. Their construction takes advantage of recombinant DNA technology, and as such they are manipulatable laboratory tools. A recent review article on DNA in medicine (Lancet 1984;II:908-911) outlines three ways to obtain a probe.
The first is used when the amino acid sequence of a gene product (a protein) is known.