There are two other important parts of the process that I didn't mention: sequencing and bioinformatics.

How sequencing machines work I have not had to figure out. You can undoubtedly Google for more info... ;-) But, once you get your little chunks of DNA replicated by PCR, you can submit them to a sequencing facility and get the actual DNA sequence. To figure out a whole genome sequence, you send off lots of little bits, and then you spend a lot of time on the computer sorting out how those bits must fit together.

Then, once you have a decent sized chunk, you compare it to the sequences in the GenBank database -- a publicly accessible database of DNA sequence information. You can find out if it's entirely new, or a variation on something else that's out there.

Then there are ways of mapping these comparisons to make phylogenetic trees to see where your bit of DNA fits in the family (or doesn't).

There's lots of computer work, and a surprising amount of eyeballing the data. The people who do it are puzzle experts.

My understanding of it all is relatively superficial, but I hope this helps.

~ Becky in L.A./Tucson