Common Reasons for Delays in DNA Testing

 Animal Search | AJSA | IGS | Fall Focus  |  ASF | Site Search

Down to the Genes Series

Everything the AJSA Needs to Know About DNA Testing

With the upcoming AJSA Regional and National Classics, and summer show season, it is very important…

Common Reasons for Delays in DNA Testing


Ways to expedite DNA test results: Communicate all required information when requesting DNA testing. Members can either request a kit when they don’t have DNA cards or TSUs, or they can request DNA testing using DNA cards or TSUs they have on hand, in which case the ASA emails paperwork specific to the member’s barcodes and samples. It is important to have all relevant information at the time of kit or DNA testing request to reduce delays in communication. Ensure proper sample collection and handling. Follow the directions for each sample type (blood, hair, tissue) in order to reduce sample fail rates or samples that don’t even make it into testing (see the adjacent page for reasons why each sample type may fail). Check out the Have You Herd blog for videos including detailed instructions to collect each sample type. Ensure proper identification on the DNA card or TSU. The barcodes on the DNA cards or TSUs are specific for the animal. If you switch animals, you must contact ASA prior to sending the sample to the lab. Why? If anything is different than expected, the samples will be held aside until the laboratory knows exactly what to test. If anything changed from the original DNA order, contact the ASA prior to sending samples to reduce confusion and delays at the laboratory. Consider priority handling or priority shipping. Members can opt to expedite animal registration or other jobs needed to complete the DNA process. Faster shipment of kits either from ASA to the member or from the member to the lab can reduce the time it takes to get results. Both of these options come at a cost. There is no way to expedite the actual testing procedure at the lab. The only way to speed up the DNA process is to reduce the time spent on kits or paperwork, sample collection, reduce sample fail rates, and reduce shipping transit times.

Ways to Delay DNA test results: Not including all required information when ordering tests. This will require follow-up emails or phone calls for ASA to obtain all necessary information. Misidentification on the DNA sample. If samples go to the lab without proper identification and paperwork, the samples are put in a “mystery box” to be deciphered by the laboratory and ASA staff. This will delay samples entering into test. Poor DNA sampling techniques. Any contamination from other DNA (blood from another animal or feces for example), chemicals such as bleach or tattoo ink, mold, or not enough sample collected can all result in samples failing testing. If samples fail testing, this will add several weeks to months to the timeline as a new kit is required, new sample collected, and retesting. See Common Reasons Why Samples Fail and Concerns by Sample Type for more information.

Common Reasons Why Samples Fail DNA Testing

General Issues Biological Contamination

• Cross-contamination between samples/animals.

• Fecal matter and dirt in the sample — any foreign material in the sample may interfere with genotyping. Chemical Contamination

• Dye/pigment from animal markers.

• Insect repellant.

• Cleaning agents. Improper Storage

• Heat exposure including leaving samples in vehicle or in hot sun.

• Exposure to foreign material including mold. • Improper frozen storage — the freeze/thaw cycle of a self-defrosting unit can degrade DNA.

• Extended sample storage — DNA degrades over time. Insufficient sample Improper shipping

Concerns by Sample Type Hair cards

• Too few or no follicles (<30) — DNA only occurs in the ‘root’ of the hair. The actual strands do not contain DNA.

• Small follicles taken from young calves — hair samples should not be taken from calves<6 months of age. Blood cards

• Insufficient blood spotted on card — ensure the circle is filled and the blood is visible on both sides of the paper.

• When spotting cards from stored blood (purple top), make sure to invert the tubes four to five times before spotting.

• Do NOT speed-dry the card using a hairdryer as heat may damage the DNA. AllFlex Tags, Typifix Tags, and Tissue samples

• No sample in unit.

• Sample is trapped in cap/does not enter tube/liquid — sample will not be preserved.

• AllFlex tags and Typifix tags should be kept at room temperature to prevent DNA degradation.

• Long-term storage (longer than one year) — store in a freezer (-20F) that does not get used often and does not automatically defrost.

Can't find what your looking for? Search for it here.