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Which read(s): 1. contain either a SNP (a single nucleotide polymorphism) or a position where different members of a multi-gene family have a different base? C 2. doesn't have any DNA? B 3. is a PCR product? A, B, and C.  All of three reads were obtained by sequencing PCR products, generated with the same set of primers. The quality plots that I refer to are here.
Since DNA diagnostics companies seem to be sprouting like mushrooms after the rain, it seemed like a good time to talk about how DNA testing companies decipher meaning from the tests they perform. Last week, I wrote about interpreting DNA sequence traces and the kind of work that a data analyst or bioinformatics technician does in a DNA diagnostics company. As you might imagine, looking at every single DNA sample by eye gets rather tiring. One of the things that informatics companies (like ours) do, is to try and help people analyze several samples at once so that they can scan fewer…