How possible is it that a DNA test from the early 1990's are inaccurate?

As far as parentage,probably not, but in the 90’s they had not yet discovered amplification, but I think parentage is simpler than that, so- to answer- it’s probably not possible- and of course you have her blood she is your mother, so your question is kind of unclear.

Just to clarify, are you saying a DNA test was done in the 90’s and confirmed who your parents are? The way I remember it is DNA testing has been available since the late 80’s so if you had a positive match then I see no reason why it would be innaccurate. Do you/did you have the actual test result?

@JLeslie Yes. And no I don’t have the results I was 4 years old

@_Whitetigress Do you think your mom would lie about it? Are you sure the test was actually done? I hope I am not upsetting you with the questions. Are you questioning it because of something physical? Like your parents have blue eyes and yours are brown, or they are both red heads and you aren’t, that sort of thing?

@JLeslie Oh no I’m positive my mom is my mom. But my dad said the results came back negative for him. He said he wants to give it another try though because the resemblance between us nearly impeccable.

@_Whitetigress Oh, I understood it was your dad that you weren’t sure about, I just thought maybe your mom had told you the results.

Do the test again so you don’t have to guess. There is always a chance of a mix up. If it had been positive for a match I would say it was almost impossible for it to be wrong, but a negative would have more chance of having a mistake, although a small chance. Think about it, if the test say yes you two share DNA like a father and son, it would have to be correct, because what is the chance if the lab mixed up two samples the other sample in the lab is actually your dad. But, if it comes up you don’t match, almost any lab error where they confuse two samples would give a negative.

Do you dread doing another test? If it is negative again would it be upsetting?

If your dad isn’t your bio father, then do you know who your bio father supposedly is?

It is unlikely.

There have been refinements to the DNA testing process and improvements that allow testing from smaller samples, but nothing that has overturned the previous science.

PCR became the standard for paternity testing in the 1990s, but I don’t know what process was used for you in the early 1990s.

I agree with @JLeslie… do the test again.

1990s they did have DNA testing, and it’s quite accurate. Before the 1960s it was trickier (when parentage tests first showed up in the 1920s it was blood-type based, which is horribly inaccurate, but since then it got better fast). If you trust that your parents are reporting the results accurately, I wouldn’t think there would be a particular reason to doubt them unless you think there was foul play involved.

That said, while highly accurate, it isn’t perfect, and there isn’t really any particular reason to not get it done again as long as the cost isn’t bad, but I would not recommend getting your hopes up if it already came back negative.