Detection and identification of Gigasporaceae from DNA extracted from soil or single spores from trap cultures by PCR-DGGE analysis of the V9 region of the 18S rRNA gene. DNA templates: lane 1, G. gigantea UFLA872; lane 2, G. gigantea VA105C; lane 3, G. ramisporophora CNPAB22; lane 4, G. margarita CNPAB1; lanes 5 to 7, soil DNA extracted from trap culture A; lanes 8 to 10, soil DNA extracted from trap culture B; lanes 11 to 14, single-spore DNA from four different Gigaspora spores recovered from trap culture A; lanes 15 and 16, single-spore DNA from two different S. heterogama spores recovered from trap culture A; lane 17, single-spore DNA from S. coralloidea recovered from trap culture A. The gel was run for 15 h at 95 V.