Read Paternity Tests
A paternity test is a DNA analysis used to determine if a man is the biological father of a child. People get paternity tests for a variety of legal, ethical and medical reasons. The DNA is collected painlessly by swabbing the inside of the cheek. Samples are collected from the child and the father at a minimum, and ideally also from the mother. Pure DNA is extracted from the specimens. Fifteen different DNA markers are compared to yield the paternity test results.
Instructions
1. Check your test for the result statement. The result statement will be worded very specifically with one of two results.
If the paternity test for "John Doe" indicates he is not the father of "James Doe," the results statement will read, "John Doe is excluded as the biological father of James Doe."
The other possible value for the result statement would read, "John Doe is not excluded as the biological father of James Doe." This is an important distinction. A paternity test can reveal a high likelihood of paternity, but never a 100 percent certainty. The result statement is based on a series of DNA profiles.
2. Review the individual DNA locus results. The paternity test compares a series of individual DNA markers, or loci, from the child, the father and the mother. The FBI's Combined DNA Index System established these markers in 1990. Individual loci list the locus name, such as "D2S1338," and the allele results for the child, father and mother as individual pairs of numbers, like "(12, 13)". These results are measurements of short tandem repeats, or STRs. At each locus, a child receives one STR allele from each parent. A biological father and their child should match at least one allele at each of these loci.
3. Review the parentage index for each locus result. Each DNA marker test will list a parentage index, a decimal number that measures the strength of a specific match, relative to how unique that match is. A higher PI indicates a stronger match. Strength is based on how often the allele value at the marker occurs in the general population. Marker alleles that don't match yield a PI of 0.00.
4. Review the combined parentage index. The CPI is the product of all the individual profile analyses. While there is no 100 percent certainty, a CPI of at least 100 is equivalent to a paternity probability of 99.00 percent. Stronger matches, like a CPI of 10,000 (equivalent to a probability of 99.9900 percent) come closer to 100 percent, but can never reach it.
Tags: paternity test, biological father, result statement, child father, father James, parentage index, biological father James
