Extraction and PCR of DNA from parasitoid wasps that have been chemically dried

Two species of parasitic wasp, Venturia canescens and Leptomastix dactylopii, were dried from alcohol using a range of methods proposed as chemical alternatives to critical point drying, i.e. hexamethyldisilazane (HMDS), amyl acetate, xylene, methyl cellusolve and acetone vapour. Also, fresh specimens of V. canescens were dried using acetone vapour, first as a fixative and then as a drying agent. Total genomic DNA was subsequently extracted and a 524 bp fragment of the mitochondrial 16S ribosomal RNA gene amplified by PCR. This indicated that all of these drying techniques yielded high-quality DNA which was amenable to PCR. The success of chemicals like HMDS as alternate rapid drying methods for wasps and other insects means that they are likely to replace critical point drying (CPD) of museum specimens in the near future. Importantly, the results from this study show that specimens, dried from alcohol using chemical techniques, are a good potential source of DNA for molecular systematics projects.