A review of PCR inibition and its mitigation in forensic DNA analysis

Abstract

Polymerase Chain Reaction (PCR) has a wide range of applications and usages in many disciplines of science. Some PCR failure can be attributed to the presence of inhibitors in the sample. Thirteen commonly encountered PCR inhibitors in forensic DNA analysis are investigated throughout this review. These inhibitors are humic substances, humin, humic acids, fulvic acids, hematin, hemoglobin, Immunoglobulin G, tannic acid, calcium, collagen, melanin, bile salts, and urea. PCR inhibitors either affect the amplification, known as amplification inhibitors, the fluorescent component, known as detection inhibitors, or a single inhibitor can produce effects through both mechanisms. In reviewing the current literature, three main methods to remove or mitigate PCR inhibition were identified; with the addition of an additive, using specialty coated magnetic beads, or using a spin column. This review discusses the advantages and disadvantages of each method and the success of each in regards to some of the inhibitors of interest.