IOSR Journal of Pharmacy and Biological Sciences (IOSR-JPBS) e-ISSN:2278-3008, p-ISSN:2319-7676. Volume 13, Issue 3 Ver. II (May. – June. 2018), PP 80-87 www.iosrjournals.org DOI: 10.9790/3008-1303028087 www.iosrjournals.org 80 | Page Testing New PCR Additives for Enhancement of Direct PCR – Based Detection of Y chromosome Stars Loci (STRs loci) from Human Hair Samples Hassab El- Nabi, S. E. 1 ; Elroby, A. M. 2 1 Genetic Engineering and Molecular Biology Division, Department of Zoology, Faculty of Science, Menoufia University, Shebin El- Kom, Menoufia, Egypt 2 General Authority of Forensic Evidence, Police Academy, Cairo, Egypt. Corresponding Author: Hassab El- Nabi, S. E Abstract: In order to evaluate the effect of adding weak hair detergent on PCR buffer for further direct PCR technique, current investigation was carried out. Hair samples were collected from five different individuals and were subjected to direct PCR technique. Two types of commercial detergents and a physical treatment (gentle scratching of outer layer of hair follicle) were added to the PCR buffer. Results showed that Direct PCR over hair samples obtained from five persons who commonly use hair waxes recorded negative results. When the detergents and the physical treatment were applied, the scale of peak heights in all loci was significantly increased. In addition, results showed that soap foam detergent considered the best treatment. Much better results for direct PCR were obtained after treating three hairs by these methods, than using only one hair. These treatments may solve the problems of rapid and cost-reducing genotyping of forensic samples as well as improving the detection efficiency for some loci and also less contaminated DNA templates, especially since most of the convicted suspects are known to use hair waxes. Key words: Direct PCR, DNA profiles, Forensics, detergents, hair. --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 24-05-2018 Date of acceptance: 08-06-2018 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction In order to obtain adequate amounts of DNA for downstream applications such as PCR, cloning, and DNA sequencing, DNA extraction is the first step in many molecular biology experiments ( Sambrook and Russel, 2001). Extraction process impose cells to liberate DNA material via physical disturbance and/or chemical processing, which is then followed by a clean-up procedure in which unwanted cellular components are separated from the DNA (Hajibabaei et al., 2005). During sample extraction, DNA may be lost due to the methods used, which can affect the quality of the DNA profile obtained ( Sawran and Welch, 2012). Direct amplification has gained increasing interest over the last few years. Newer, more robust amplification kits claim to perform direct amplification better and faster than kits previously available in the forensic science community. However, most of the commercially available amplification kits require pre-treatment of the body fluids with buffers or washing reagents prior to amplification (Hall and Roy, 2014). In 2010, Shokralla et al. hypothesized that a small amount of DNA oozes from the tissue into the preservation solution (usually ethanol), and that this DNA was amplifiable using a standard PCR protocol. They considered the preservative ethanol could be used as a source of genetic material for non-invasive analyses or when DNA analyses are required for specimens that have been consumed in prior experiments. They also succeeded to perform their hypothesis and performed amplification to DNA of the agave butterfly larvae, Hypopta agavis that presented in mescal (liquor). A primary advantage of direct amplification without purification of DNA is the reduced analysis time and higher throughput of databank samples (Hall and Roy, 2014). Current methods for detection of short tandem repeat (STR) profiles from reference samples can employ direct polymerase chain reaction (PCR) amplification of body fluids bound to swabs, FTA ® and/or non-FTA ® (fast technology for analysis) substrates. Most collection media for storing dried body fluid samples contain cell-lysing chemicals to preserve DNA within a sample that may contain PCR inhibitors (Burgoyne, 1994). Concerning human samples, it is currently limited to amplifying blood and buccal stained FTA ® cards using specially designed multiplex kits in forensic DNA. These multiplex kits have improved buffer-polymerase systems which are more tolerant to inhibitors present on FTA ® samples (Swaran, 2014). Furthermore, PPY23 System is configured with the majority of the highly discriminating loci with smaller amplicon sizes. Due to smaller amplicon sizes even, trace amounts of DNA can be amplified and the discrimination potential of partial profiles can be maximized (Thompson et al., 2013). The PPY23 System provides all the necessary materials to amplify the Y-STR regions of human genomic DNA (Jain et al., 2016).