Abstract: Use of a lithium salt, particularly lithium thiocyanate, as an agent for lysing red blood cells and denaturing hemoglobin in the performance of an immunoassay to detect the relative amount of a hemoglobin derivative in a blood sample. The method is particularly useful in the determination of hemoglobin Alc. The method provides a rapid means for releasing hemoglobin from red blood cells by lysis and for exposing the epitope that is characteristic of the Alc form. Low concentrations of the lithium salt provide rapid release and denaturation of hemoglobin without the need for dilution prior to the performance of the immunoassay.

Abstract: Use of a lithium salt, particularly lithium thiocyanate, as an agent for lysing red blood cells and denaturing hemoglobin in the performance of an immunoassay to detect the relative amount of a hemoglobin derivative in a blood sample. The method is particularly useful in the determination of hemoglobin A1c. The method rapidly releases hemoglobin from red blood cells by lysis and exposes the epitope that is characteristic of the A1c form. Low concentrations of the lithium salt provide rapid release and denaturation of hemoglobin without the need for dilution prior to the performance of the immunoassay.

Abstract: A method for chemically coupling a controllable number of ligands, e.g., haptens, to a polymeric material by derivatization of the polymer with an activating agent to introduce a couplable functional group. The derivatization is performed in the presence of a blocking agent which is reactive with the same functionality on the polymer as the activating agent. By reacting the polymer with a mixture of a predetermined ratio of excess amounts of the activating and blocking agents, a controllable number of couplable functional groups are introduced to the polymer for subsequent linkage to the desired ligand. The resulting polymer-ligand conjugates are useful as reagents in immunoassays, particularly immunoturbidimetric assays.

Abstract: A latex agglutination immunoassay method for determining an analyte in a blood sample in which the pH of the reaction mixture is maintained at about 8.5 or greater in order to overcome nonspecific agglutination of latex particles by hemoglobin present in the sample. The method is particularly applicable to the determination of glycated hemoglobin, e.g., Hb Alc. In another embodiment, native hemoglobin (Ao) can be determined based on its ability to cause agglutination of latex particles suspended in an aqueous solution having a pH of about 8 or below.