An assay for a single SNP. Contains the experimental parameters that
distinguishes this assay from assay for other SNPs designed using the same protocol
(primers, extension probe etc., depending on the experimental protocol). The assay
input and output parameters are largely platform-specific. See example assays in the
/xml-examples/ directory. IMPORTANT! the plan is for all groups to submit an assay
record for all attempted assays, not merely the ones that were successful. The
status for such failed or otherwise unsuccessful (e.g. rejected prior to design
phase because of repeats in area).. The point of this exercise is that the DCC can
calculate all sorts of useful stats (most notably overall assay conversion rate) if
we have a record of every attempted assay.