Paternity testing uses DNA analysis to ascertain whether or not a man is the father of a particular child. A DNA sample can simply be collected by swabbing the inside of the cheek of the mouth to obtain a cheek cell sample of both the child and man, since DNA is found in all the cells of the body. The Polymerase Chain Reaction (PCR) test is used to analyze the DNA sample in the lab. The DNA in the test tube is separated from the sample by removing all the other components of the cell including proteins. The PCR process utilizes DNA polymerase to replicate copies of specific DNA strands. There are 3 steps in the PCR process:
1. Separation of the DNA strands is done by heating the material to 90 -96 0C in order to denature the specific genetic material into two double helix DNA chains. When the two strands separate, each strand is used as a template when a copy is made by DNA polymerase.
2. At 55 0C, a short sequence of nucleotides attaches to the ends of the DNA strands.
3. The temperature of the test tube is increased to 75 0C, and a complete copy of each DNA strand is made (replication).
The specific target loci of the father and child DNA sample is examined and compared. Two numbers are generated one will match the biological mother’s numbers and the other the biological father’s numbers.
Probability of paternity value of 99.99% means that the man tested is the biological father of the child.
Probability of paternity value of 0% means that the man tested is not the biological father of the child.
-nandi and marissa