In one embodiment, the invention is to a dry reagent composition configured as a solute to be dissolved into whole-blood prior to a whole-blood immunoassay, the dry reagent composition comprising: goat IgG, mouse IgG, dextran, a buffer, proclin, and sodium chloride in a support matrix. In another embodiment, the invention is to a dry reagent composition configured as a solute to be dissolved into whole-blood prior to a whole-blood immunoassay, the dry reagent composition comprising dextran and a salt in a support matrix.
