Application of a combination of neutral red and amido black staining for rapid, reliable cytotoxicity testing of biomaterials.

Cell viability and growth for cytotoxicity evaluation of materials for prosthetic devices has been tested using various methods. The aim of this study was to extend the choice of reliable methods to quantify cytotoxicity of materials in vitro. By measuring both viability and growth of cells exposed to biomaterials in vitro, two different parameters are analysed and quantified upon reading of the absorbance of coloured solutions in a spectrophotometer. Neutral red uptake and amido black staining of cells have been used for cell viability and cell number measurement, respectively: they have been found to be well correlated with the number of surviving cells. These methods have been adjusted to a 96-well microplate cell culture system and re-evaluated as simple and reliable methods for the quantitative assessment of biomaterial effect on cells.