Lab on a Strip: Developing a Novel Platform for Yeast Biosensors
The Pacific Ocean is home to a wide range of marine life, including the food source of many filter-feeders, toxin-producing algae. When algal blooms are ingested by shellfish, the toxins produced by the algae are caught within shellfish tissue. Although these toxins are harmful to us, they aren’t to the shellfish, giving collectors no immediate sign of danger. Biotoxins are also just generally difficult to detect; contrary to popular belief, algal blooms are not always the striking crimson of “red tides.” Thus, blooms may not be discovered until after a poisoned shellfish is found. The Washington State Department of Health and commercial shellfish farmers conduct periodic surveys of local beaches to catch contaminations early, but these methods are costly, time-consuming, and not always effective. This can especially pose a dilemma for individual shellfish hunters, who do not have the resources to screen their shellfish for toxins. With current detection methods, the crowds swarming to Seattle’s famous Pike Place Market and popular raw oyster bars are constantly at risk.
We have developed a much cheaper diagnostic tool in which genetically-modified baker’s yeast is grown on a paper device and is able to produce an easy-to-read color output in the presence of a target molecule. Imagine if you could simply dip a sheet of paper into your bucket of shellfish, wait only (insert amount of time) and tell if your products are safe to consume. The proof-of-concept systems we’ve engineered detect the plant hormone auxin and the molecule theophylline. However, we’ve implemented a number of techniques to ensure the versatility of our systems thus, they can be easily modified and further developed to test for a wide variety of other molecules.