The MTT assay is a colorimetric assay for assessing cell metabolic activity. The Bradford assay is a colorimetric assay that measures protein concentration. They are convenient colorimetric reagents for biochemical redox reactions. These antibodies are typically detected with chemiluminescent, fluorescent or colorimetric assays. Some methods for quantification of total phenolic content are based on colorimetric measurements. Some methods for quantification of total polyphenol content are based on colorimetric measurements. This assay measures the reducing potential of the cell using a colorimetric reaction. The test may be performed as a quantitative colorimetric test using a spectrophotometer. Transducer techniques include&colon; electrochemical, piezoelectric, colorimetric, and optical spectrometric systems. The NBT/BCIP reaction is also used for colorimetric/spectrophotometric activity assays of oxidoreductases. Other newer methods use colorimetric or fluorescence-labeled technology in the place of radioactive isotopes. Randox's range of reagents covers many different techniques such as colorimetric, UV and immunoturbidimetric methods. These methods usually include a combination of sensorial, biochemical, mechanical, and colorimetric (optical) measurements. Silica is measured on side stream samples with colorimetric analyzers. Detection methods are usually colorimetric or chemiluminescence based.