A COMPARATIVE STUDY OF FOUR DNA EXTRACTION PROTOCOLS FROM ADDUCTOR MUSCLE IN GOLDEN MUSSEL (Limnoperna fortunei)

The golden mussel, Limnoperna fortunei, is a mollusk native to Southeast Asia and a highly invasive species in South American countries such as Brazil, Uruguay, and Argentina. In order to better understand the biological behavior of the species and develop alternative control methods, genetic studies involving the optimization of DNA isolation procedures are of utmost importance. The objective of the present study was to develop a simple, reproducible, free of contaminants, and cheap protocol to extract DNA from L. fortunei using the adductor muscle of the mussel as the source. Four DNA extraction protocols were compared: extraction with SDS and proteinase K (P1); extraction with SDS, proteinase K and phenol (P2); TRIzol extraction (P3); and NaCI, SDS and RNase extraction (P4). DNA concentration (ng mu L-1) and purity (at 260/280 nm) were measured using a spectrophotometer. DNA purity and amplification were verified by electrophoresis and PCR, respectively. P1 resulted in samples with low DNA concentrations or without any DNA, as revealed by the quantification and purity analysis; P2 had low efficiency, given the absence of DNA in most of the samples subjected to electrophoresis. On the other hand, P3 showed contamination with proteins, as indicated by an absorbance of <1.8 and by the low-quality electrophoresis results. Finally, P4 resulted in well-defined bands, absorbance between 1.8 and 2.0, and successful amplification by PCR. In conclusion, the extraction protocol P4 is a practical, fast, free of contaminants, and efficient method for the isolation of L. fortunei DNA.