By Eulalee Thompson 
A strand of hair or the quick swabbing of the inside cheeks may be all that is required to confirm the paternity of a child.
GENTLY RUBBING a swab on the inside cheek of a child, and those of his mother and putative father, will produce enough genetic material for the scientist working in a properly-equipped laboratory to determine the child's paternity.
The samples taken from the inside cheeks contain the individuals' DNA (Deoxyribonucleic acid), the genetic material coiled in the chromosomes of cells in the body. Except in the case of identical twins, an individual's DNA is unique, just like a fingerprint. The DNA molecule makes exact copies of itself passing on genetic information to the daughter cells when the cell divides.
It is because one's DNA material is so unique that Dr. Grace Haynes, consultant haemotologist, can say confidently that in the science of DNA paternity testing there's really little room for error. The results of paternity tests are presented in almost absolute terms 99.9 per cent inclusion (that the man tested is the father) or zero per cent exclusion (the probability that the man is not the father).
Except for sperm cells and egg (ovum) cells, every nucleated cell in the body has 46 chromosomes 23 chromosomes each coming from the sex cells of one's biological mother and father and in the chromosomes, the scientists will locate the DNA material. Tissue, blood, semen and cheek cells samples used in DNA paternity testing store genetic material that will confirm lineage. Dr. Haynes said that because DNA testing is very sensitive and great emphasis is placed on accuracy, the chain of custody of the samples collected is very critical. Samples can be easily contaminated even by accidentally brushing the swab against another surface.
After a detailed interviewing process of the parties involved, along with positive identification, consent forms, birth documents and other relevant papers, Dr. Haynes sends her samples to a U.S. laboratory, approved by that country's Centres for Disease Control (CDC).
"There are strict guidelines set by U.S. Centres for Disease Control (CDC) for collecting samples and for the chain of custody of the samples, to prevent contamination and corruption of the results," she emphasised.
In the laboratory, the experts will test for properties of the DNA that frequently differ from person to person (taking into consideration that the DNA of any two human being is more than 99 per cent identical). The DNA is extracted from the sample, which is cut into fragments using enzymes. The DNA fragments go through a process until the unique band pattern of the child is revealed half of this pattern should match the mother and the other half, the true father.
In countries such as the United States and United Kingdom, a standardised system of test has been developed which enables the DNAs of different individuals to be matched by a computer from an expanding database.
