Transplantation is based on a satisfactory matching of the patient and donor genes for Human Leukocyte Antigen (HLA), which increases the chance of a successful transplantation. HLA gives individual cell surface markers. The Major Histocompatibility Complex (MHC) region, encoding HLA in humans, is the most polymorphic in the human genome. The genes are located on chromosome six and consists of 200 genes. Those genes encode protein products essential for the acquired immune system. MHC molecule’s role is to represent foreign substance for B- and T-lymphocytes. MHC is an important system as it contributes to the activation of the immune system to combat viruses, bacteria, parasites and cancer cells. HLA-typing is determined through certain antigens in the HLA system. The classical transplantation antigens are HLA-A, -B, -C, -DR, -DQ and -DP. By amplifying the DNA with sequence specific primers in the Polymerase Chain Reaction (PCR), the amplicons can be detected and alleles present in the patient genome can be determined. The purpose of this study was to compare occurrence of non-specific DNA binding using master mix where Ampli Taq DNA polymerase is added and master mix with polymerase included in the PCR. Samples from 16 patients were tested with both master mix- solutions. The analyses were performed with primer plates for HLA-A, HLA-B and HLA-DRP1. The results showed that the master mix with Taq polymerase included should be applied, because it gave clearer specific band, better image quality and gave weaker and approximately 30% fewer non- specific DNA binding compared to the master mix with added Taq polymerase.