Recently, the AHDC has received ear notch specimens for BVDV antigen capture ELISA (ACE) testing that produced a yellow color in the extraction buffer. The color of the substrate used in the ACE test is also yellow. As a result, a high per cent of the samples were scored as low positive in the test. Additional testing indicated the samples were negative.

We suspect that an iodine solution made its way onto the specimens. We strongly recommend not permitting the ear notches to come in contact with any product that could generate a color in the test fluid.