DNA fingerprinting and forensic medicine.

In forensic medicine, DNA fingerprinting for identification is becoming a necessary procedure. A method to radiolabel M13 DNA probe by primer extension using a specific oligonucleotide primer was developed. The method specifically labeled the two 15 bp repeats in M13 DNA which hybridize to target DNA giving rise to DNA fingerprinting patterns. The M13 probe labeled by this method has proven useful for individual identification, paternity testing and monitoring reconstitution in bone marrow transplantation. The genetic locus D1S80 and D17S30 containing a variable number of tandem repeats (VNTR) have also been successfully amplified from human genomic DNA isolated from blood (50 ng from each sample) by the polymerase chain reaction (PCR) using oligonucleotide primers complementary to the flanking sequences as primers for amplification. DNA bands were detected by ethidium bromide staining after electrophoresis on agarose gels. Analysis of this VNTR locus was thus achieved without the need for Southern blot or radioactive material. The small size of the DNA fragments produced in the PCR amplification permited good resolution of individual alleles. The precise specification of the number of tandem repeats present in each allelic fragment was reproducible from one analysis to another.