Materials and methods
Sets of 4 fingerprints were imprinted on 10 cm 10 cm glass plates, glossy magazine papers, and plastic sheets, and then dusted with red, green, and yellow fluorescent powder (Lynn Peavey, USA). Wet swabs were used for fingerprint collection. DNA samples were extracted by 2 methods; the QIAamp1 DNA Mini Kit (Qiagen,USA) and Chelex1 100 extraction method [5]. DNA was quantified
TM using NanoDrop 1000 Spcetrophotometer (NanoDrop Technologies, USA) by measuring absorbance at wavelengths of 260 and 280 nm. Purity of the DNA samples was evaluated using the A260/ A280 ratio.
DNA samples were pre-analyzed using a fluorescent triplex PCR primer set, consisting of THO1, D8S1175, and CSF1PO primers published in the STR base. Expected PCR products are in the range of 150–370 bp. Triplex PCR amplification is according to Thamnurak et al. The 16-STR loci typing was performed in a total reaction volume of 12.5 ไมโครL using AmpF‘STR Identifiler PCR amplification kit (Applied Biosystems, USA). For low copy number typing, the number of PCR cycle was increased from 28 to 34.