Specificity and sensitivity of random amplified polymorphic DNA analysis for the identification of single larvae of Trichinella after experimental infection of pigs.

Single muscle larvae (ML) of Trichinella belonging to 5 species and 2 genotypes collected from 126 experimentally infected pigs and preserved in 75% ethyl alcohol at room temperature were identified by random amplified polymorphic DNA (RAPD) analysis to evaluate the specificity and sensitivity of this assay. A double-blind protocol was used to ensure that the interpretation of electrophoretic patterns after RAPD amplification was not influenced by an expected result. RAPD analysis of one larva from each sample showed a sensitivity of 100% when only samples with undamaged DNA were considered, and the specificity resulted in an 88% match with the species or genotype that had been used to infect pigs, whereas the identification reached 100% specificity when an additional one to four ML were examined.