What is the difference between genetic testing such as FISH and DNA testing?

[Music] what is the difference between genetic testing such as fish and dna testing so you know fish is able to look at large segments of dna you know things that are big enough you can see it with your under a microscope uh but you know most of the the uh dna is way too small to see under a microscope it consists of nucleic acids and the way we see nucleic acids is we we sequence them and so there's been a you know revolution in sequencing and we can sequence much more now than we ever could before and so that has allowed us to use genomic testing on the dna to look and and there's there's many many different kinds but i would think probably the most widespread would be what's called a sequencing panel where a select number of genes might be 100 or 200 have been selected because of their importance and those ones have been sequenced to look to see if they contain point mutations that would alter the function of the gene the other kind of genetic testing that might be done would be called whole exome or whole genome and what that means is the whole exome you take all of the portions of the dna that code for proteins and you sequence that to see if you find a mutation or the arthritis whole genome where you take all the dna including the 95 which is seems to be garbage and sequence that uh and both those techniques are useful and can tell you different things what is sequencing your genes are consist of dna and dna is a series of nucleic acids that we summarize as gatc and sequencing is just a way of converting the the molecule dna into a series of letters that we can add gatc that we could analyze on the computer how does ngs identify mutations the best thing to do in sequencing is to compare the sequence of the tumor dna to normal dna from the same person and then you look to see if there's any differences sometimes it's it's not practical or cost-effective to sequence the normal dna from the same person and then you base your findings based on the frequency of any given change if it's never been seen in a normal person before then you could assume that it's probably in the tumor