How reliable is DNA paternity testing? I've read 99.9% for inclusions and 100% for Exclusions. Is that Correct

DNA paternity testing is very accurate. Using PCR techniques and RFLP (restriction fragment length polymorphisim) a laboratory can tell to within x percentage of the population (depending on your genetic background) that you are or are not the father. If the child is male, they can also do Y-chromosome testing, which would match only to you, since the child can only get a Y-chromosome from the father, and not the mother.

Very few things in life are 100 percent. And things that involve processing in a lab will be less than 100 percent for sure, because you can have simple human error (they mix samples), or complex human error (they mis-tune a piece of equipment and you get out of what results that still seem believable).

I think the 99.9 percent that labs quote excludes all forms of human error, so the real thing must be closer to, say, 97 or 99, at best.

They have that 0.1% wiggle factor because although they look at a lot of genetic sites when they do the testing, there is always a possibility, however small, that someone else has that exact same genetic pattern. Also, this gives the lawyers something to quibble over and keeps them busy and out of everyone else's way.

The exclusion is 100% because even one difference will disqualify you, and this disqualification is a certain thing.

Theres a .01 percent margin of error so it will never say 100 percent anything.

It will say chances are 99.9 percent that you are or 99.9 percent that you aren't the child's father.

Either way if it says you are 99.9 percent probably the child's father - unless you have a twin brother who's also having sex with the lady, then it is your child!

Pretty close, but they don't state it this way. It is usually something like probablility ----- the probability is 1 in 500,000 that this person is not the parent. Or: The probability is 7 out of 10 that he is.. Or that x % of this area in the DNA samples match.....

It is 100% in exclusion unless there is a contamination of the sample being tested.

Yes it's very reliable!!!!!!!!!!!!!!!!!