Does the ELISA test change a dark color like black or grey to clear?

The ELISA (enzyme-linked immunosorbent assay) test does not involve a color change from dark (black or grey) to clear. Instead, it typically involves a color change from colorless to colored, indicating the presence or absence of the target analyte being detected.

In an ELISA test, a series of steps are followed, which include:

1. Coating of the microplate wells with the capture antibody specific to the target analyte.

2. Addition of the sample or standard containing the analyte.

3. Incubation and washing steps to allow for the binding of the analyte to the capture antibody.

4. Addition of a detection antibody conjugated with an enzyme (e.g., horseradish peroxidase or alkaline phosphatase).

5. Incubation and washing steps to allow for the binding of the detection antibody to the captured analyte.

6. Addition of a substrate specific to the enzyme used in the detection antibody conjugate.

7. Incubation and stopping steps to allow for the enzymatic reaction and color development.

The final step results in a color change, which can be measured spectrophotometrically at a specific wavelength. The color change is typically from colorless to a visible color, such as yellow, blue, or red. The intensity of the color is proportional to the amount of analyte present in the sample.

Therefore, in an ELISA test, the color change is from colorless to colored, not from dark (black or grey) to clear.