| 摘要 |
A composition for an enzyme-linked assay is described which comprises a chromogenic substrate that produces a detectable color with a maximum absorbance at one wavelength in reactions of the assay which contain the enzyme and a pH indicator dye that produces a detectable color with a maximum absorbance at a second wavelength when the pH of the reactions of the assay is changed to terminate the reactions. The chromogenic substrate enables colorimetric detection of the bindable substance in positive reactions of the assay and the pH indicator dye enables negative reactions of the assay to be colorimetrically distinguished from false negative 3,3',5,5'-tetramethylbenzidine (TMB) and the pH indicator dye is preferably selected from the group consisting of cresol red and m-cresol purple. |
