STR, Loci, and DNA Markers - huh?
If you are searching for a paternity testing company, chances are that this is the first time you’ve been exposed to the DNA testing industry. You are probably encountering many new terms, especially scientific language, that can be confusing as you consider your options.
Some of the most common scientific terms you will run into are DNA marker, STR, and loci (or the singular form, locus). These terms are closely associated with each other, so it can be difficult to determine what they mean and why they are significant.
DNA markers, or genetic markers, are specific DNA segments for certain genetic characteristics. Scientists will identify the types of DNA markers they want to study based on the research they are performing. For paternity testing, scientists will use STRs.
STR stands for short tandem repeat. As the name implies, STRs are short, repeating sequences of DNA. The number of repeats in each sequence is variable from person to person. Because of this variability, STRs are useful for identifying people based on their unique genetic profile (a profile of a person’s DNA markers).
The more DNA markers that are tested, the more accurate a test can be. The international DNA database, CODIS, uses 13 standard markers for DNA testing. Beta routinely tests 16 DNA markers and has the capability to test more if extended testing is necessary.
The term “loci” (which is the plural form of “locus”) comes from the Latin word for “place.” The loci are the locations of genes on the chromosome where DNA testing companies locate and test DNA markers. There are hundreds of loci on most chromosomes.
In short, at specific loci, STRs (which are the DNA markers) are tested by comparing their lengths.
Biologically related individuals will have the same STR lengths at specific loci. In a biologically related trio (mother, child, and father), half of a child’s markers will be the same length as the biological father, and the other half will be the same length as the biological mother.
Learn more about Beta’s paternity testing services and order your free test collection kit by contacting us today.
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on Tuesday, March 27th, 2007 at 2:06 pm and is filed under Home Paternity Tests.
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