This product includes 1 ml of 10x Assay buffer, 0.1 ml of 20 x Reagent A, 0.1 ml of 20 x Reagent B, 0.5 ml of 10x Reagent C and 0.020 ml of 10 mM NADH.
The assay measures micromolar concentrations of NADH. NADH is the reduced form of nicotinamide adenine dinucleotide (NAD). NADH is an enzymatic cofactor for many reductases and acts as an electron donor. It is a product of many oxidases using NAD as an electron acceptor. Both NADH and NAD are involved in many biosynthesis and degradation pathways. The MicroMolar NADH Assay Kit (NADH100) provides a convenient tool for sensitive detection of NADH. The assay is based on detection of light absorbance at 590 nm and the assay process is completed within 20 min. It is in a 96-well plate format and can be used for high throughput screening of enzymes involving NADH. The assay is compatible with most common buffers in biochemistry labs. It is not compatible with NADPH or other reducing reagents such DTT.
The MicroMolar NADH Assay Kit (Catalog No. NADH100) includes 1 ml of 10x Assay buffer, 0.1 ml of 20 x Reagent A, 0.1 ml of 20 x Reagent B, 0.5 ml of 10x Reagent C and 0.020 ml of 10 mM NADH. It is for 100 assays in a 96-well plate format.
ASSAY PROTOCOL
The following assay protocol is based on using a 96-well plate for the measurement. The sample volume is 100 µl and the final assay volume is 190 µl. It can be reformatted in a 384-well plate assays or using a cuvette by adjusting the volumes accordingly.
STANDARD CURVE
1. Reagent dilution and sample preparation: Dilute the 20 x stock solutions 20-fold with water. Dilute the 10 x stock solutions 10-fold with water. Prepare 100 µl of NADH solutions in the wells of a clear 96-well plate with a two-fold serial dilution from 100 µM to zero in 1 x assay buffer.
2. Detection: Into the 100 µl of the NADH solutions, add 20 µl of 1 x Reagent A, then 20 µl of 1 x Reagent B. Incubate the mixture at room temperature for 10 min then add 50 µl of 1 x Reagent C and read the light absorbance at 590 nm.
3. Data Analysis: Plot the light absorbance Ac and the NADH concentration [NADH] to generate the linear standard curve.
Ac = a [NADH] + b
Where the Ac values are from experimental data, the a and b values are from the linear fitting between the Ac values and the NADH concentrations.
UNKNOWN SAMPLES
Follow the same procedure to measure the light absorbance Ac values from the unknown samples. Calculate the NADH concentrations in the unknown samples using the Ac values from the unknown samples and the a and b values from the standard curve.