Abstract: Urinary porphyrin levels are assayed as a diagnosis technique for many disorders and abnormalities. Selective separation and quantitation of coproporphyrins (COPRO) and uroporphyrins (URO) are accomplished by adsorbing urine on an anionic exchange resin and selectively eluting the COPRO then the URO from the resin, followed by the determination of the amount of COPRO or URO in the respective eluates. In preferred methods the COPRO eluate is a diluted HCl and the eluate for URO is a more concentrated HCl; and the amount of COPRO or URO is determined quantitatively by fluorometric comparison with known concentrations of COPRO.

Abstract: A barrier device, advantageously utilized to separate blood serum from other components by centrifuging, and preferably in the form of a truncated cone having stabilizer posts extending from the conical base in the direction of truncation and an axial post extending from the opposite, concave side is disclosed. A strip of pliable material having complementary depressions therein serves as a package and dispenser for the barrier device. Insertion into a test tube is preferably accomplished by placing the test tube in the opening of the depression and ejecting the barrier device by pressure against the post through the pliable packaging material.

Abstract: Blood serum is separated from other components of whole blood by inserting a barrier device having a specific gravity between that of the blood serum and the other blood components into a centrifuge containing a sample of whole blood, and centrifuging until the barrier device migrates to a position intermediate the blood serum and the other blood components. The preferred form of the barrier device is a truncated cone having stabilizer posts extending from the conical base parallel to the axis of the cone in the direction of truncation.