A simple protocol for the extraction of total DNA from minute amounts of tissues and subsequent amplification of specific sequences by polymerase chain reaction is presented. The method is applicable to a wide variety of vegetative tissues such as leaves, single needles and rootlets, cell suspensions, and also single sexual embryos and megagametophytes derived from a variety of gymnosperms and perennial angiosperms. Amplification of DNA is shown using pairs of primers specific to genes that encode the small ribosomal subunit.