Evaluation and In-House Validation of Five DNA Extraction Methods for PCR-based STR Analysis of Bloodstained Denims

  • Henry Perdigon
  • Gayvelline Calacal
  • Kristine Co Seng
  • Saturnina Halos
  • Maria Corazon De Ungria


One type of crime scene evidence commonly submitted for analysis is bloodstain on denim. However, chemicals (e.g., indigo) used to produce denim materials may co-purify with DNA and hence, affect subsequent DNA analysis. The present study compared five methods (e.g., standard organic, organic with hydrogen peroxide (H2O2), modified FTA™, organic/Chelex®-Centricon®, and QIAamp® DNA Mini Kit-based procedures) for the isolation of blood DNA from denim. A Short Tandem Repeat (STR)-based analysis across two to nine STR markers, namely, HUMvWA, HUMTH01, D8S306, HUMFES/FPS, HUMDHFRP2, HUMF13A01, HUMFGA, HUMTPOX, and HUMCSF1PO, was used to evaluate successful amplification of blood DNA extracted from light indigo, dark indigo, indigo-sulfur, pure indigo, sulfur-top, and sulfur-bottom denim materials. The results of the present study support the utility of organic/Chelex®-Centricon® and QIAamp® Kit procedures in extracting PCR-amplifiable DNA from five different types of denim materials for STR analysis. Furthermore, a solid-based method using FTA™ classic cards was modified to provide a simple, rapid, safe, and cost-effective procedure for extracting blood DNA from light, dark indigo and pure indigo denim materials. However, DNA eluted from bloodstained sulfur-dyed denims (e.g., sulfur-top and sulfur-bottom) using FTA™ procedure was not readily amplifiable.

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