Labrador Retriever Forum
2wks on average
Is that the turnaround time, or the time it actually takes to do the test? Again, I'm not asking what the average turnaround time is. I am asking if they were working only on my sample and had it in hand, how long the actual testing process takes from set up to getting results. 24 hours? 48 hours?
I think only Optigen can answer that question. Why don't you email or call them?
To my knowledge, electrophoresis is used. A sample is put in a gel and a low current is applied to the gel. The markers for the genes migrate through the gel and when complete they are read. The time it takes for total migration of the sample through the gel depends on the labs protocols. More than likely a few days but the range could be one day to a week.
I took 2 females right to Optigen after the vet saw them at Cornell and drew the blood we took it over to the optigen building where they do the testing dropped it off had my results in a little over 48 hours by email that was the fastest ever for me. But Dr.Riess did the eye exams first and then drew the blood to be dropped off. No long lines while I was there and they said blood on the way from a clinic lab specialty and they would pick up To Funny felt like in a grocery store after a snow storm!
She said take at least 48 hours after they start on each individual test!
Sorry not to respond earlier to a question in my area of expertise - I've been whelping a litter.
In order to do any kind of DNA analysis you have to have a marker, a place that differs in the DNA. Currently there are three types of markers commonly in use. These are restriction polymorphisms, PCR polymorphisms, or single nucleotide polymorphisms. I don't know which type they are using for the Optigen test. If it is a restriction site, they need to digest the DNA with an enzyme and then run it on a gel using electrophoresis as Sharon said. One version of the gene has the site and the other doesn't, so the DNA fragments are different lengths, which the gel separates. These procedures would take less than three hours. My students do that in a three hour lab. However, the Optigen test uses a blood sample, so it would have to be purified before that, as hemoglobin inhibits the enzymes.
If they are using PCR (polymerase chain reaction) it might take longer. For such a test they would have to take the treated DNA and add it to a mixture containing an enzyme that makes DNA plus little pieces of DNA called primers. The DNA-making enzyme (called Taq polymerase) can't start from scratch- it has to have something to add onto, so by using the right primers, you can get the exact part of the DNA that you want to be made. PCR uses two primers, bracketing the piece of DNA to be tested. The mixture is put into a machine that cycles through several temperatures that allow the enzyme to replicate the DNA over and over. You have to use a piece of DNA that differs in length in different subjects (for the Optigen test, the PCR gene would be linked to a marker of one length and the normal gene to a different length) and separate the replicated pieces on a gel. The person who thought this system up got a Nobel prize for it! My students do this, too, using their own DNA. It takes about an hour to get DNA from a check swab and only 30 minutes or so to set the PCR up for these inexperienced users, but the replication can take several hours and then you still have to run it on the gel. We usually let the PCR run overnight and do the electrophoresis in the next lab period.
If they are using a single nucleotide polymorphism, they have to actually sequence the DNA. This would require extensive purification of the DNA, a procedure similar to PCR except that you use one primer instead of two, plus fluorescent chemicals that are attached to the last subunit of DNA to be added to the chain. The DNA is electrophoresed in a very expensive machine that detects fluorescent markers on those last nucleotides and constructs the sequence from them. This would probably be an overnight thing. Obviously I'm way oversimplifying here. This procedure can be tricky.
Two days sounds reasonable for the minimum amount of time to do the entire procedure, possibly longer if they are doing sequencing.
