摘要 |
Improved, catalyzed substrates for use in developing characteristic colors of florescence in the presence of peroxidase enzymes (e.g., horseradish peroxidase) are disclosed which include as a rate accelerator a substituted phenol such as a p-halogenated phenol. The complete substrate typically includes a peroxide type oxidizing agent (e.g., hydrogen peroxide), a chromogenic or fluorogenic compound (e.g., ABTS), a buffer and the accelerator compound. Advantageously, the accelerator should provide at least about 50 percent rate enhancement for the substrate, as compared with an otherwise identical, accelerator-free substrate reacted under the same conditions; however, the most preferred accelerator, p-iodophenol, gives enhancement on the order to 1,000 percent. The substrates are particularly useful in so-called ELlSA determinations which involve an enzyme-linked moiety, and permit detection at very low concentration levels unobtainable with conventional colorimetric substrates. |