Method of inhibiting nonspecific reaction in pivka-ii assay reagent

A reagent for measuring concentration of PIVKA-II through an agglutination reaction comprising:

• first carrier particles to which a first monoclonal antibody is immobilized;
• second carrier particles to which a second monoclonal antibody is immobilized;
• and
• divalent metal ions,
• wherein one of the first and second monoclonal antibodies is an antibody specifically binding to PIVKA-II while the other is an antibody specifically binding to prothrombin,
• wherein the both antibodies bind to different epitopes, and
• wherein the divalent metal ions are ions of one or more selected from the group consisting of Be2+, Mg2+, Ca2+, Sr2+, Ba2+, and Ra2+.

A kit of parts for measuring concentration of PIVKA-II through an agglutination reaction comprising:

• a first reagent containing divalent metal ions;
• and
• a second reagent containing first carrier particles to which a first monoclonal antibody is immobilized and second carrier particles to which a second monoclonal antibody is immobilized,
• wherein one of the first and second monoclonal antibodies is an antibody specifically binding to PIVKA-II while the other is an antibody specifically binding to prothrombin,
• wherein the both antibodies bind to different epitopes, and
• wherein the divalent metal ions are ions of one or more selected from the group consisting of Be2+, Mg2+, Ca2+, Sr2+, Ba2+, and Ra2+.