SEQUENTIAL MULTIPLEX AMPLIFICATION (SMA) OF GENETIC-LOCI - A METHOD FOR RECOVERING TEMPLATE DNA FOR SUBSEQUENT ANALYSES OF ADDITIONAL LOCI

A method called Sequential Multiplex Amplification (SMA) has been deve loped whereby a limited amount of DNA extracted from a sample can be r eutilized for several single polymerase chain reaction (PCR) amplifica tions. The method involves recovery of genomic template DNA by microfi ltration of PCR-amplified samples. Up to 5 different loci have been ty ped, each in a single system PCR-based assay, beginning with a test qu antity of 5 ng template DNA. Genotypes of the DNA donors were compared with those obtained from individual amplifications and shown to be id entical. This could be a useful technique for typing a number of loci from a limited amount of DNa and to recover template DNA from samples previously subjected to PCR. Obviously, when small quantities of templ ate DNA are available, this technique can prove quite useful.