DNA Testing Laboratory
The Arryst Biosciences laboratory uses state-of-the-art equipment and proven techniques. The methods employed by the laboratory undergo rigorous quality assessments, and modifications to these methods are implemented only after extensive quality assurance and research. All reagents used, whether they are purchased from a commercial supplier or manufactured in-house, undergo regular quality control inspection. Consumers can be rest assured that the laboratory is performing at a high standard of quality.
Arryst Testing Laboratory
Arryst Testing Laboratory, located in San Jose, California, processes all of the Early Gender DNA Test samples. Because the process is extremely delicate, time-and-labor intensive, and requires skill and experience, we do not contract out to other laboratories to process our samples.
Several standards and quality control procedures are in place to guarantee that our results exceed your expectations:
Every new reagent is thoroughly tested.
We keep track of our boy:girl ratio to ensure it is within an acceptable range from published birth rates.
Any case of an incorrect result is thoroughly investigated to understand the errors and make necessary improvements to the Early Gender test.
Results are only released if they pass strict standards. In fact, not every customer gets a result on the first test.
In the Laboratory
Each sample goes through a three-step process including:
Amplification with Arryst unique biomarkers
DNA Extraction and Purification
After the dried blood sample arrives in the laboratory, the blood-soaked filter paper is cut into small pieces. The DNA is extracted from the filter paper and then washed to remove impurities such as protein and cellular debris.
Depending on how much blood fills the circles on the filter paper we can process samples 2-6 times. Each sample is purified a minimum of two times to validate results. If there is not enough blood for at least two purifications then a retest is required.
With each set of samples purified, a blood sample from a female who is not pregnant is processed as a negative control. If male DNA is detected in the female processing control then male DNA may have been introduced into the processing procedure and all data from this set of samples is discarded.
The purified DNA is put in an amplification reaction (PCR). In this reaction, DNA is multiplied 240 times. PCR requires knowledge of the DNA sequence of interest. Based on published knowledge of Y chromosomal DNA, we can target amplification of a specific portion of the Y chromosomal DNA. If no Y chromosomal DNA is present in a sample, no amplification occurs.
Each result is validated by redundant tests:
For each portion of a sample processed, we detect three different areas of Y chromosomal DNA in order to assure accuracy.
In addition, amplification of each of the three areas is run in triplicate before the results are analyzed.
For each amplification reaction:
We detect total purified DNA to insure that enough DNA is purified.
We test whether the reaction is efficient or not (inhibition).
We have a positive and a negative control to make sure the amplification reagents are working correctly.
Highly Sensitive Arryst Test
Our amplification reagents are very sensitive and specific. The blue curve is a dilution of male genomic DNA. As the diagram indicates, very low levels of male DNA are detectable with the Arryst Early Gender Test - even less than 1 genome equivalent (that’s about one cell!). The pink curve is a dilution of female genomic DNA. Even very concentrated amounts of female DNA result in low levels of background.
Samples are analyzed only if all quality control measures pass inspection. The ability to detect Y-chromosomal DNA amplification may sound simple but in reality, there is an inconclusive range where we are not able to determine a result. Reasons for inconclusive results are:
Samples with no Y-chromosomal DNA still have background levels of amplification.
Some women may have very low levels of fetal DNA due to rapid clearance of the cell-free DNA from their blood.
If these background levels of amplification are higher than expected or if levels of male DNA are low then the sample is inconclusive.
We will not release results of samples with an inconclusive result unless the sample is purified at least two additional times with a clear result.