| abstract |
An improved device and method of separating the cellular components of whole blood from plasma or serum and assaying the plasma or serum for a predetermined soluble constituent are disclosed. The device includes a filter pad, that separates the cellular components of whole blood from the serum or plasma, and a test pad, that assays the serum or plasma for a predetermined soluble constituent. The filter pad effectively separates and retains cellular components of the whole blood sample, thereby eliminating assay interference by the cellular components of whole blood. The method includes contacting the whole blood with a test device including a filter pad comprising a suitable carrier matrix homogeneously incorporating therein a separating reagent composition comprising a) separating reagent, like an agglutinin, such as a blood type nonspecific lectin; a coagulant, such as a thrombin or a thrombin-like compound; or a mixture thereof, and b) a nonhemolytic surfactant, like an ethoxylated or propoxylated nonionic or anionic surfactant, such that the cellular components of the whole blood are separated from the plasma or serum as the blood permeates through the filter pad, The essentially cell-free plasma or serum then saturates a test pad that is in contact with the filter pad. After the plasma or serum saturates the test pad, the test pad is examined for a qualitative or quantitative response to a predetermined soluble constituent of the whole blood. |