Serotech Laboratories Ltd. - DNA Testing and Analysis
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Who's the dad?  Don't just guess, know.

About DNA Testing

What is DNA and what does Paternity Testing look at?

DNA, the genetic blueprint, is composed of a string of 3 billion individual units called nucleic acids, of which there are four kinds.  The exact order of these units, called the sequence, is unique to all individuals except identical twins.  DNA is subdivided into 23 paired structures called chromosomes. One of each pair of the child’s chromosomes is derived from the mother and one from the father.  DNA is the same from cell to cell in any given person and is passed along from parent to child according to the principles of Mendelian genetics, whereby one of each pair of chromosomes passes from parent to child in an independent fashion.

In the laboratory sixteen different paired regions of DNA are individually examined from the mother, child and presumed father.

These regions have been carefully chosen because they show great variability in size (number or units) from person to person.  Thus the sequence inherited by a child from its mother usually differs from that from its father in each of these variable regions.

Testing delineates which half of the child’s DNA derives from the mother and the other half is examined to see if it matches that of the putative father.

How are Paternity Test results reported?

Exclusion from paternity is indicated when the child’s DNA does not match that of the presumed father.  In this case the probability of paternity is given as 0%.

If the analysis does not exclude the presumed father, it does not necessarily indicate that he is the genetic father.  His genetic makeup may be identical to that of another man in the general population, who may be the genetic father.  In this case, Serotech computes the statistical probability that the accused is the true genetic father of the child.  This statement of probability is based on the frequencies of the regional chromosomal sequences studied in large, randomly selected population of a given race. The laboratory will calculate how many other men in the population possess the combination of regional chromosomal sequences of the specified DNA marker regions paternally inherited by the child, and express the result as a percentage that indicates the probability of paternity of the accused man compared to that by a group of randomly chosen men in the population.

The statistical probability of paternity for a man not excluded from being the biological father of the child is typically greater than 99%.


To schedule an appointment for DNA testing, or discuss your testing needs, please contact us by phone at 1-877-DNA-5556 or by email. Our knowledgeable staff will answer any questions you may have and help you schedule an appointment. Sample collection is available across Canada, the United States, and around the world.

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