Laminar Flow As A Tool To Unlocking The Past

The laminar flow cabinet has become a widely used tool in archaeology, not so much to protect workers as to protect the specimens they are working on. Contamination from 21st-century DNA sources, such as plant pollens, could render the results worthless.

Archaeologists use the laminar flow bench in the same way forensic biologists do because although the risks to human health are minimal compared to those posed by, for example, a recently deceased cadaver. Any retrievable DNA data must be protected from cross-contamination at all costs.

Laminar flow reveals 3,000-year old drug problem

While forensic investigators are well aware of the risks posed by recreational drugs such as cannabis, there was seemingly no need for a class 2 cabinet when a 2,700-year-old “stash” was discovered in a Chinese tomb.

Perfectly preserved due to the extremely arid conditions, the ancient plants (which had retained their green chlorophyll) yielded some surprising results when a laminar flow cabinet was used to run genetic analysis tests on them in a British laboratory. While the distinctive odour had long since gone, the specimens still yielded relatively high traces of THC (Tetrahydrocannabinol, the active constituent that causes cannabis’ psychotropic effects). Although an attempt to cultivate the seeds proved unsuccessful, this told scientists that the plant had been cultivated as a “pharmacologically active agent,” possibly for its psychoactive properties, and not – as scholars originally believed – for making hemp baskets and rope.

Recent advances in DNA extraction have enabled the laminar flow bench to unlock ancient secrets in everything from olive stones to human bones.