James Joseph Emerald said:
I have a question, assuming what you're describing is a blood lab:
I am, I just left the Otherworld Filter(TM) on.
James Joseph Emerald said:
How are forensic samples handled? Does it make any difference?
I'm doing a course in criminal investigation, and they always mention the "blood & semen lab", but I'm wondering if there's any actual distinction between a forensic lab and a "normal" one.
Well, I assume this varies from country to country (and probably, in the US, from state to state), so take this with a pinch of salt:
The only forensic evidence I've personally handled (so far) has been urine for drug testing and blood for paternity testing. The only semen I've handled has been for standard fertility testing (spermogramme, bacterial culture, microscope analysis, the usual stuff), which has nothing to do with the law. In both cases, you have to follow some REALLY strict protocol, because anything that can be proven as a mishandling of the evidence can be grounds for a mistrial or just end up smearing the lab's good name. So in general, the biochemist in charge of the lab drops the paperwork and important administrative stuff they're currently doing and does the lab stuff themselves. The only exception has been the drug testing, which is so simple and common that we're allowed to do it ourselves (but we still have to notify them and they come and observe the results themselves, and often take it upon themselves to deliver the report).
In general, the forensic evidence an ordinary lab can handle depends on what sort of testing they do. Anything that involves forensic DNA testing is probably going to get sent to labs that have the equipment for it, which are generally labs that specialise in genetics (though not necessarily aimed at forensics). Urine drug testing is something any lab can do, as the equipment for doing so is really simple to use and even an untrained person can use them (they work somewhat like pregnancy sticks for urine). Serum drug testing is a bit more complicated, because while most labs probably have the necessary machinery for it, most don't bother buying the reagents for drug testing unless they have enough weekly samples to justify the cost (which means they will probably just pass it on to a lab that is known for doing that kind of thing). At the place I work, we only have the reagents for a handful of drugs, and they're not for forensics, but to monitor treatment (lithium, phenytoin, vancomycin).
And then there's also the fact that, for what I've heard from the biochemists that run the labs I've worked at, forensic stuff is generally something most blood labs avoid, since in general the risks of having a pack of wild, rabid lawyers coming down on you and dragging you and everything you've worked for through the mud, are rarely worth it.
So in general, most blood labs are going to pass on anything forensics related because they either don't have the equipment, don't have the reagents, or don't want to get involved in legal stuff, which means that some labs are going to be set up exclusively as forensic labs and will receive most of the forensic samples.
As for the "distinctions" there aren't that many. A machine that runs drug serum levels can also do stuff like HIV antibodies, oestrogen levels, CK-MB levels and so on, so a "normal" lab can buy it for some things and a forensic lab can buy it for others, with the difference being the type of reagents they buy. The equipment for DNA testing can also be repurposed for non-forensic things, like viral/bacterial DNA testing, or histocompatibility testing, genetics research and so on. Forensic toxicology equipment can be used for workplace toxicology, accidental toxicology, endemic toxicology and the like.
In the end, it's more of a "do I want to get involved in this sort of thing" decision for the people in charge of the labs, and for most of them, the answer is a "no."
Nothing motivates a person more knowing they're getting paid by the hour to study.
