Trypan Blue, 0.4% Solution In PBS
Trypan Blue is a blue acid dye with a strong affinity for cellulose containing substrates such as cotton; less affinity for proteinaceous materials. Trypan blue solution may be used in trypan blue based cytotoxitiy and proliferation assays. Trypan Blue is used as a vital dye which is especially important because it is taken up by the reticuloendothelial system. Clark describes assays for the study of teratogenic action of trypan blue on embryonic tissues using Davis and Sauter's fluorescence method and for the staining of collagen, including very fine fibrils, muscle and cornified epithelium using the Van Gieson method. Trypan blue is also recommended for use in dye exclusion procedures for viable cell counting. Non-viable cells will up-take trypan blue at a faster rate than viable cells.
Phenol Red, 0.5% Solution
Phenol red is an acid-base indicator. It is made by condensing two moles of phenol with one mole of o-sulfobenzoic acid anhydride. Phenol red in tissue culture media can act as a weak estrogen, especially with human breast cancer cells. Phenol red can be used to measure hydrogen peroxide in cultured macrophages in multiwell plates.