Simple performance of the planar SOS-Umu-C–FLD genotoxicity bioassay shown for perfume and packaging material analysis

Abstract

Planar bioassays are powerful, sustainable tools for nontargeted detection of hazardous compounds in complex samples. They provide more information on a sample than corresponding in vitro assays and are more sustainable in terms of plastic material and solvent consumption. However, instrument investment costs for high-performance thin-layer chromatography are high. Hence, the question arose of whether the sophisticated sensitive planar genotoxicity bioassay could be performed manually without instrumentation under simple conditions. Cheaper plate types were studied as well as manual application of the samples, cell suspension, and substrate solution. As a result, genotoxic compound zones were detected as rose-colored or orange fluorescent resorufin end-product formed upon contact of the genotoxins in tested perfume and packaging materials with a genetically modified Salmonella Typhimurium strain. The simple performance was found to be possible for low sample application volumes. Knowledge on neutral pH value and thickness of the adsorbent layer were further key aspects. Manual spraying was found to be superior to manual immersion if excess liquid was avoided. For high sample volumes and a higher level of standardization, the open-source 2LabsToGo system was proposed as excellent option for low investment costs. Its very low instrumental footprint and the straightforward prioritization strategy help analytical chemistry to balance between technology and nature/ecology to reduce the instrumental footprint and planetary overshoot.

Antimicrobial non-porous surfaces: a comparison of the standards ISO 22196:2011 and the recently published ISO 7581:2023

“…In our opinion, the use of an aerosol chamber would allow a uniform and reproducible application method with a fast drying time ( Ronan et al, 2013 ). As already show in our laboratory, spraying bacterial suspensions with a simple manual pump spray or with an automatic TLC sampler allows a homogenous distribution of the bacteria on the test plate ( Windisch et al, 2024 ).…”