Standard molecular techniques, with only a slight modification, are very useful in obtaining and interpreting the final results in the field of forensic genetic. Data obtained through such analysis are highly reliable and can be used as a very powerful tool that produces valuable results. However, success and swiftness of DNA typing of biological evidence either that found at a crime scene or used in disputed paternity testing, depends on the optimization of numerous factors. One of the most important and critical phases that ensures reliability of the whole procedure is the choice of the most suitable volume for the amplification protocol. Buccal swabs were collected from volunteers. DNA was extracted by Qiagen Dnaeasy Tissue Kit. PowerPlex 16 kit was used to simultaneously amplify 15 STR loci by PCR. Amplification was carried out as described previously. The tested total working reaction volumes were 5, 10 and 25 microl. The PCR amplification was carried out in PE Gene Amp PCR System Thermal Cycler (ABI, Foster City, CA). Amplification products were analyzed on an ABI PRISM 377 instrument (ABI, Foster City, CA) in 5% bis-acrilamide gel. Amplification was generally successful for all the tested reaction volumes. Lower partial to complete DNA profiles ratio, the quality of obtained STR profiles, significantly reduced amount of reaction's components give advantage to 5 microl reaction volume over other two tested volumes in this case.

All 193 tested individuals have been involved in legal proceedings concerning various forensic testing. Buccal swabs have been taken as the DNA source and Chelex procedure was used for DNA extraction (1). The PowerPlex 16 kit (Promega Corp., Madison, WI) has been used to simultaneously amplify by PCR 15 STR loci. The STR loci are: D3S1358, TH01, D21S11, D18S51, Penta E, D5S818, D13S317, D7S820, D16S539, CSF1PO, Penta D, vWA, D8S1179, TPOX and FGA. Similar amounts of DNA have been used in all PCR reactions. Amplification was carried out as described previously (2).

POPULATION: We have analyzed the distribution of allele frequencies at 12 Y-chromosornal short tandem repeats loci (DYS 19, DYS385a, DYS385b. DYS389I. DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439) in the representative sample of Bosnian and Herzegovinians. A total of 100 unrelated male individuals (Caucasians) from different regions of Bosnia and Herzegovina have been sampled for the analysis. Samples were collected with a respect to the approximate proportional participation of three main ethnic groups in Bosnia and Herzegovina [Bosniacs-Muslim (35). Serbs (31), Croats (34)].