A simple and rapid modified-new method for DNA extraction of FTA bloodstains

Objective To establish a simple and rapid new method for DNA extraction of FTA bloodstain samples.Methods Genomic DNA was extracted from FTA bloodstains of 1.2mm diameter by FTA-DNA direct extraction and FTA routine method respectively,and their genotypes were analyzed using ABI IdentifilerTM kit in 10μl and 25μl of reaction volume respectively.Results For 25μl of reaction volume,all DNA extracted by two different methods was successfully genotyped.For 10μl of reaction volume,however,the typing success rate of DNA extracted by FTA routine method was significantly lower than those by FTA-DNA direct extraction procedure.Using FTA routine method,the value of RFU ranged from 100 to 2000,and the peak imbalance result from preferential amplification of the smaller allele was a common phenomenon.Moreover,allelic dropout occurred in approximately nineteen percent of samples,and this was not obviously improved even if performed by automatic DNA workstation.However,using FTA-DNA direct extraction procedure,the typing results were similar to those in 25μl of reaction volume,and better results can be obtained using automatic DNA workstation.Conclusion The FTA-DNA direct extraction method is simple and rapid,and can be used to automatic establishment of DNA database with FTA bloodstains.