Dideoxy fingerprinting of low-level nucleotide variation in mitochondrial DNA of the human blood fluke, Schistosoma japonicum.

Dideoxy fingerprinting (ddF) is an efficient method for the detection of sequence changes in polymerase chain reaction (PCR)-amplified DNA fragments. It is a hybrid between single-strand conformation polymorphism (SSCP) and dideoxy sequencing, employing only one dideoxynucleotide in the reaction. We report the application of ddF for the display of low-level nucleotide variation in the mitochondrial (mt) NADH dehydrogenase subunit 1 (ND1) (404 bp) in the human blood fluke, Schistosoma japonicum. Variant samples differing by 1-6 nucleotides could be readily differentiated from one another by their characteristic and reproducible ddF profiles. The findings indicate the potential of this method to screen for point mutation in any parasite genes.