Considerations for colorblind individuals on selecting colorimetric or fluorescent dye assay outcomes.

A disadvantage of colorimetric detection in nucleic acid amplification assays is the possibility that a colorblind individual may interpret colors differently than observers with full-color vision. Using an isothermal amplification assay, the ability of colorblind individuals to distinguish between positive and negative results for four dyes was tested. Five individuals with self-reported colorblindness and four with full-color vision reported their observations of the color of the solution. Although colorblind individuals may accurately interpret assay results, they were often not accurate in reporting the color. Hydroxynaphthol blue was the most problematic dye, and both phenol red and SYBR™ green were less troublesome. Consideration for colorblind individuals is warranted when developing an assay and training staff in its performance.