Cheek Swabs Now Accepted by OptiGen – April 2007

Concerns and Caveats

 In response to the clear desire voiced by many of OptiGen’s current and potential clients, we have added the option to submit cheek swabs as a DNA source for our tests.  We appreciate that this change will make the process of submitting a sample simpler and less costly for our clients.  However, there are important factors you should consider when deciding whether to send us a blood sample or a cheek swab.

• Risk of Sample Contamination:  This concern has been the primary reason that OptiGen has resisted accepting cheek swabs for so long.  The DNA tests that we perform are extremely sensitive and even a small amount of contamination (e.g. from another dog or a human) could easily result in erroneous test results.  It is of utmost importance that the cheek swab DNA sample is collected with this serious concern in mind and that every effort is made to prevent any contamination of the sample during the collection and shipping process.  Instructions must be followed exactly and carefully.
• Insufficient DNA Obtained:  This concern arises from the possibility that too few cells may be scraped from the cheek during the collection.  If there are not enough cells collected, then not enough DNA will be obtained and the tests will not work properly.  Insufficient DNA would most likely be a result of the collector not properly following the instructions, however other factors could influence this.  Some dogs may be difficult to handle and prevent a good contact between the swab and the cheek. Also, some dogs have relatively more saliva than others and this may prevent a good adherence of the cheek cells (that are the source of the DNA) to the swab.
•  Incorrect Identification of the Dog:  Unlike the controlled clinical setting required for a blood sample collection by a technician or a veterinarian, cheek swab samples can be collected almost anywhere, anytime and by anybody. This is their obvious advantage…as well as their obvious disadvantage if one is concerned with the possibility of erroneous identification of the animal being named in a test report.  In an effort to highlight this risk, we have modified our test report so that the source of the DNA sample (“Blood” or “Swab”) will be listed directly below the test result.  We have also modified the signature page of our order form to require a “Witness” to verify the dog’s identity.   It should be noted that some breed clubs or health registries may not accept cheek swabs as a source of DNA for certain health tests.
  
  It is the responsibility of the client to check on the specific requirements of each breed club or registry.
  
  
• Some tests are not suitable for Cheek Swab Samples:  Cheek swab samples are not suitable for certain tests offered by OptiGen.  These tests currently are: 
  • CL
  • CLAD
  • CSNB
  • Cystinuria
  • Narcolepsy
  • PK
  • PFK
  • rcd1-PRA
  • rcd3-PRA

On rare occasions over the years, we were unable to isolate sufficient high quality DNA from a blood sample to complete testing on that sample. In these isolated cases, OptiGen has requested that the client send us a second blood sample and then we repeated the extraction and testing of this second blood sample at no additional cost to the client.  We will continue to honor this policy for blood samples.  Due to the higher likelihood that cheek swab samples will yield insufficient DNA, we can not extend free-retesting for cheek swab samples. The full test fee will be charged if a second cheek swab sampling is submitted to replace the first failed sampling. We will, however, allow a replacement submission of a blood sample at no additional charge if the first cheek swab sample fails to yield sufficient DNA.

No Long-Term Storage

The option for long-term storage of sample DNA is not available with cheek swabs due to the low quantity of DNA extracted from such a sample. If long-term storage is desired, a blood sample must be submitted.

No Excess DNA Stored

Optigen has stored excess DNA from a blood sample and relied on that for quality assurance and opportunities to offer a second genetic test for a breed. This benefit is not possible with cheek swab DNA. If additional tests are developed for a breed, new sample will be required.

***Sampling Puppies****

Cheek swab samples from puppies under about 8 weeks of age – that is, before weaning, are not advised due to the possibility of maternal contamination and/or puppy-to-puppy contamination. OptiGen is not able to detect trace contamination in these samples and clients assume risk of incorrect test result due to contamination of cheek swabs from pups prior to weaning.  If puppies must be tested prior to weaning, a blood sample is strongly advised.