Syrian hamster embryo (SHE) assay (pH 6.7) coupled with infrared spectroscopy and chemometrics towards toxicological assessmentThis article is part of a themed issue on Optical Diagnosis. This issue includes work presented at SPEC 2010 Shedding Light on Disease: Optical Diagnosis for the New Millennium, which was held in Manchester, UK June 26th–July 1st 2010.

The Syrian hamster embryo (SHE) assay (pH 6.7) is an in vitrocandidate to replace in vivocarcinogenicity tests. However, the conventional method of visual scoring of foci (non-transformed vs.transformed colonies) can be time-consuming and is open to subjectivity. Infrared (IR) spectroscopy has the potential to provide objective assessment of such SHE colonies with the added advantage of potentially providing mechanistic information. In this study, SHE cells were treated with one of eight different chemical regimens, allowed in culture to attach and form foci on IR-reflective glass slides; these were subsequently interrogated by attenuated total reflection (ATR) Fourier-transform IR (FTIR) spectroscopy. Derived mid-IR spectra (n= 13 406) were subjected to chemometric analysis focusing primarily on the extraction of biochemical information related to test agent treatment and/or morphological transformation. The use of ATR-FTIR spectroscopy with chemometrics to analyze the SHE assay is a novel approach to toxicological assessment. [ABSTRACT FROM AUTHOR]