i'm phil torres and today i'm here with kyle, lindsay and rachelle. going to start with a story of how we can use our dna in medicine . rachelle, what do you have? >> i submitted my dna for a company called 23andme. let's find out. >> simple test, nothing complicated. the first thing i have to do is take the tune and i get to fill it with slief hav splie saliva. you can watch me spit. that's done. i joined 23 million people who sent their saliva to 23andme. to conduct a personal dna test. they begin with our 46 chromosomes, 23 from each parent, filled with you're dna. dna is a double helix with base pairs of nucleotides. as paired with cs. >> katy: , g s.over and over. so that a sequencing machine has enough material to determine the exact order of those as ts gs and cs. >> that's the instruction manual for what makes you you, and me me, and other people themselves. when we sequence dna, we are determining the order of those bases then you match them up to a reference. you match up to where you differ from the reference sequence. and those changes are