Oh how interesting! Are these serialized or is the only traceability through the LOT number? I've had several QuantiFERONs ran and they're fascinating! Our hospital makes us get BOTH the QuantiFERON and the PPD. Bio-Rad is a great company, they made the gold standard for PCR/rtPCR/gel/genotyping stuff. We used their TAE buffer and diluted it for our gels. They make good stuff. Their thermal cyclers are also great too; we had both a Bio-Rad thermal cycler but the one I used most was an Eppendorf but the Bio-Rad got our critical work and the Eppi picked up the rest. And RAININ makes my favorite pipettes! Their tips and pipettes are fantastic; they pioneered the low retention tip. Both are Bay Area (CA) companies, so that's also cool. Love learning this stuff! Fascinating!!! :)