“Direct PCR” optimization yields a rapid, cost-effective, non-destructive, and efficient method for obtaining DNA barcodes without DNA extraction

Macroinvertebrates that are collected in large numbers pose major problems in basic and applied biodiversity research: identification to species via morphology is often difficult, slow, and/or expensive. DNA barcodes are an attractive alternative or complementary source of information. Unfortunately obtaining DNA barcodes from specimens requires many steps and thus time and money. Here, we promote a short-cut to DNA barcoding; i.e., a non-destructive PCR method that skips DNA extraction (“direct PCR”) and that can be used for a broad range of invertebrate taxa. We demonstrate how direct PCR can be optimized for the larvae and adults of non-biting midges (Diptera: Chironomidae), a typical invertebrate group that is abundant, contains important bioindicator species, but is difficult to identify based on morphological features. After optimization, direct PCR yields high PCR success rates (>90%), preserves delicate morphological features (e.g., details of genitalia, and larval head capsu...