Flow cytometry offers the possibility to simultaneously analyze, on a cell by cell basis, different parameters related to cell viability i.e. cell size, morphology and incorporation of dyes. Different types of analysis: light absorption of unstained/stained cells, forward angle light scattering (FALS), right angle light scattering (RALS) or both, cell fluorescence based on dye retention or dye exclusion (due to erythrosin B, ethidium bromide, fluorescein diacetate, rhodamine 123) were tested and compared, with the classical Trypan blue exclusion test, for their effectiveness in the determination of cell viability. Two types of cells in monolayer cultures (L929, SIRC) and a freshly isolated suspension of mouse splenocytes were used. For each dye, the optimal dose, incubation time and conditions for analysis were determined. Viability indications by different techniques for the three type of cell line and their reliability as compared with Trypan blue were analyzed.
The in vitro agarose overlay method was investigated as an alternative to the Draize eye irritation test for the evaluation of the ocular irritancy of cosmetic products. Modifications to the original protocol include the definition of an area of lysis (expressed as a weighty)/toxicity relationship for each product by a planimetric method and the creation of an agarose classification. 56 different cosmetic formulations, including emulsions, gels, lotions and tonics, were evaluated using this modified test, and the results were correlated with in vivo Draize data. Four different agarose classes were delimited: non-irritant; minimally irritant; mildly irritant; and irritant; corresponding respectively to the following scoring scales (x 10 4g): 0; 0 <x<200; 200≤ x <450 and ≥ 450. A high correlation between the agarose overlay method and the Draize test was observed when taking into account two classes: non-irritant (non-irritant, minimally irritant) and irritant (mildly irritant, moderately irritant [Draize] or irritant [agarose]) as shown by an 86% concordance value. In this study, the sensitivity was 92% (11–12 irritants were predicted by the agarose diffusion method) and the specificity was 84%. The overestimation error of 16% suggests that the agarose overlay method might be slightly more sensitive than the Draize eye test. When applying the kappa test, the agarose overlay method reached a 64% coefficient, attesting that the good correlation with the Draize test was not due to chance. In relation to the Landis & Koch classification, this percentage places the agarose overlay method in the “good concordance” class. Based on these results, the use of the agarose overlay method for screening the ocular irritation potential for the cosmetics industry can be considered to be a very interesting alternative to be included in a battery of tests.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.