Colorimetric assays general introduction

All of these assays are read at 570 nm (except for the AP assay, for which the 

It is important to remove any bubbles from the wells before absorbance readings. 

A All the dyes/substrates should be handled and disposed of as if they were considered mutagenic. 

At end of the cell growth period, remove medium and rinse the wells in 100 JLl of PBS. 

Incubate for 2 h in a humidified incubator in 5% 00 195% air at 37°C. Read plates at 405 nm, and either reincubate for a further time if increased sensitivity is required or stop with addition of 50 xl well of 1 M NaOH to cause an electrophilic shift in the p-nitrophenyl chromophore and thus develop most of the yellow colour, giving greatly increased sensitivity. 

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