This product includes 1 ml of 100 x dye A43, 100 ml of Reagent 1, 0.5 ml of 100 x Reagent 2. It is for measurement of 1000 samples using 96-well plates. A cuvette may also be used for the measurement of detergent concentrations.
The Detergent Assay Kit is for detection of various detergents at concentrations below their CMC values for most detergents. The concentration response is different from detergent to another. The assay is based on the principle that the detergent interacts with dye A43 and enhances the fluorescence intensity at 535 nm (excitation at 485 nm). The assay is compatible with most buffers and salts. It is not compatible with phosphate. Molecules such as ATP or ADP that release phosphate may interfere with the assay.
The assay kit (Catalog number DAK1000) includes 1 ml of 100 x dye A43, 100 ml of Reagent 1, 0.5 ml of 100 x Reagent 2. It is for measurement of 1000 samples using 96-well plates. A cuvette may also be used for the measurement of detergent concentrations.
The assay is sensitive to dodecyl maltoside but it is not sensitive to alkyl saccharide detergents with short alkyl chains such as octyl glucoside and nonyl glucoside. For octyl glucoside, please use Beta Octyl Glucoside Assay Kit (catalog number: OG100K). For nonyl glucoside, please use Beta Nonyl Glucoside Assay Kit (catalog number: NG100K).
The assay kit is not sensitive to low concentrations of SDS. For SDS, please use NanoGram SDS Assay Kit (catalog number: SDS200).
ASSAY PROTOCOL
The following protocol is for assays using a standard black 96-well plate (Costar 3915 or Greiner 655076). Adjust the assay reagent volumes proportionally for measurements using cuvettes.
1. Prepare standard detergent solutions with a series of concentrations from 0.001% to 0.1% in water or a buffer. Prepare 1 x dye A43 by dilution of the 100 x dye A43 with Reagent 1 (100-fold dilution). Each assay needs 100 µl of 1 x dye A43. Prepare 1 x Reagent 2 by dilution of the 100 x Reagent 2 with water (100 fold dilution). Each assay needs 50 µl of 1 x Reagent 2.
2. Mix 50 µl of the detergent solution with 100 µl of 1 x dye A43. Then add 50 µl of 1 x Reagent 2 and mix the solution for 2 min.
3. Read the fluorescence at 535 nm (excitation at 485 nm). Plot the correlation between the fluorescence values and the detergent concentrations and compare the data from the unknown samples.