Snake Venom Forensics


In the science fiction classic Bladder Runner, Harrison Ford's character  Rick Deckard tracks down a replicants (synthetic humans) using a scale from an artificial snake. The planet has been turned into a sewer, and most of its life forms other than humans have been obilterated. While we have not quite reached the level of environment degradation depicted in the film, we are consuming snakes at an alarming rate. For a variety of purposes including meat, skins, and venom.

The illegal trade in snake parts in many places in the world has increased in spite laws and legistation to protect snakes. Last August there was a story posted on this blog regarding the illegal trade in snake venom.

A raid on a hotel room in Kerala recovered  the venom and the the local magistrate sent venom samples to the Center for Cellular and Molecular Biology in Hyderabad. The smugglers were charged with illegal hunting and trafficking of a protected animal, both punishable by a prison sentence and fine of 25,000 rupees (about $500). The case is still pending.

 Now Indian scientists (Sing et al. 2012) at the Centre for Cellular and Molecular Biology in Hyderabad have developed a technique of identifying the species of snakes that produced a venom sample.  Their analysis used the primers for cytochrome b frpom the mitochondrial DNA genome and revealed that the venom was extracted from  Indian cobras (Naja naja). On the basis of this report, the  authorites were able to file charges against the accused for illegal hunting of the protected cobra and smuggling of snake venom. This approach potential for rapid identification of snake venom recovered by law enforcement. This paper is also the first report of DNA isolation from dried snake venom for species identification.

Extraction of DNA from snake venom  is difficult because when a snake voluntarily injects or ejects its venom, it usually does not contains snake cells. However, when humans exteact the venom by force tissues of the venom gland are most likely damaged and DNA becomes available from the cells mixed with the venom.

You know its only a matter of time before this becomes a plot on CSI, or one of its spin-offs.

Citation
Singh, C. S., Gaur, A., Sreenivas, A. and Singh, L. (2012), Species Identification from Dried Snake Venom. Journal of Forensic Sciences. doi: 10.1111/j.1556-4029.2011.02049.x

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