Bioluminex-Analyze for the needle not the haystack!

Verbitski, S. M.; Gourdin, G. T.; Ikenouye, L. M; McChesney, J. D. Rapid Screening of Complex Mixtures by TLC Bioluminescence. Am. Biotech. Lab. 2006, Apr (Accepted for Publication).

The screening of complex mixtures such as foodstuffs, beverages, dietary supplements, and waste water for toxins and adulterants or potential biological activity is often expensive and time consuming.  To identify the active or toxic constituents in such mixtures requires the tedious isolation of single components followed by assays of their biological effects.  Alternatively, standard rapid-screening tests only establish the overall toxicity of a mixture disregarding the identification of the active culprit.  Additionally when these materials are tested in their mixture condition there is a high risk of artifacts or false data due to interferences and interactions with other components in the mixture. Optimally, a rapid screening assay which analyzes activity of the individual components of a mixture in an economical and efficient fashion would be of great value.  The Bioluminex™ (ChromaDex, Santa Ana, CA) assay, which is based on direct bioautography is one such technique.

Weins, C.; Jork, H., Toxicological Evaluation of Harmful Substances by In Situ Enzymatic and Biological Detection by High-Performance Thin-Layer Chromatography. Journal of Chromatography A, 1996, 750, (1-2), 403-407.
The efficiency of a chromatographic analysis method is determined by the selectivity of the chromatographic separation and the specificity of the detection method. In the case of high-performance thin-layer chromatography (HPTLC) the separated components can be detected and quantified directly on the chromatogram by physical and chemical methods. By coupling high-performance thin-layer chromatography with biological or biochemical inhibition tests it was possible to detect toxicologically active substances in situ. A linear relationship was shown between the signal of the inhibition of cholinesterase and the concentration of the inhibitor using a constant enzyme concentration and a constant incubation time. The graph of the inhibition of the luminescence of Photobacterium vibrio fisheri in relation to the concentration of pentachlorophenol (range 20–80 ng) is nearly linear. Measurements were done by using a densitometer or a videodensitometric scanner.

Eberz, G.; Rast, H. G.; Burger, K.; Kreiss, W.; Weisemann, C., 1996. Bioactivity Screening by Chromatography Bioluminescence Coupling. Chromatographia 43, 5-9.

Because luminescent microorganisms change their light emission in the presence of bioactive substances, they provide an effective way of monitoring toxicity. Here we report the direct coupling of bioluminescence to chromatography which is capable of detecting single toxic components in complex mixtures. Two approaches were investigated, utilizing thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC).  The TLC-bioluminescence imaging technique was developed into a versatile and rugged method and proved to be superior to the HPLC-based design.  Employing genetically engineered luminescent bacteria gives customized selectivity of bioactivity detection. The combination of analytical separation technology with the biospecific sensing ability of living cells provides a novel screening tool for targeting bioactive components in complex samples.