seriously... blood is actually a little harder to get dna from as hemoglobin is a PCR inhibitor..
ok so how these tests work...
they are checking for non coding DNA.. so they are NOT looking for the genes that give golden retievers yellow hair, or the wrinkles on a bassett... they are looking in the 'junk' DNA.
They don't look at all of it.. just a an infintesimally small part of the junk DNA.. then they run it though a computer and it somes back and says that statistically your dog has repeats in the non coding dna most similar too "insert breed here" now how do they know what breed is most similar too? Well they have a database of known purebred dogs.. but the issue is that if your dog is from different bloodlines, etc etc it won't come up.
THe part that is flawed is the statistical part.. it doesn't matter if you extract the DNA from buccal cells, blood cells, or any other tissue.. the DNA itself will be the same (well barring chimerism) the fact is there are no genes that say "JRT, or Akita"
I am sure you have heard of CODIS.. there was a case where a black man and a white man shared the same 12 out of the 13 loci that CODIS checks for.. they aren't related in anyway, not even of the same ethnicity... so if we can't do it for humans with a HUGE database.. there is no chance for us to do it reliably with canines.
ok so how these tests work...
they are checking for non coding DNA.. so they are NOT looking for the genes that give golden retievers yellow hair, or the wrinkles on a bassett... they are looking in the 'junk' DNA.
They don't look at all of it.. just a an infintesimally small part of the junk DNA.. then they run it though a computer and it somes back and says that statistically your dog has repeats in the non coding dna most similar too "insert breed here" now how do they know what breed is most similar too? Well they have a database of known purebred dogs.. but the issue is that if your dog is from different bloodlines, etc etc it won't come up.
THe part that is flawed is the statistical part.. it doesn't matter if you extract the DNA from buccal cells, blood cells, or any other tissue.. the DNA itself will be the same (well barring chimerism) the fact is there are no genes that say "JRT, or Akita"
I am sure you have heard of CODIS.. there was a case where a black man and a white man shared the same 12 out of the 13 loci that CODIS checks for.. they aren't related in anyway, not even of the same ethnicity... so if we can't do it for humans with a HUGE database.. there is no chance for us to do it reliably with canines.