The invention relates to modified immune globulins, a process for preparing them by treating immune globulins in a slightly acidic to neutral solution with a molar excess of a primary amine and a carbodiimide or salts thereof and pharmaceutical compositions containing modified immune globulins.

Amino lower alkyl ethers of the phenolic hydroxyl group of opium alkaloids are linked via a peptide linkage to carboxylated latex polymers to form reagents which are useful in a sensitive diagnostic test to detect the presence of opium alkaloids in body fluids.

A method and compositions are provided to effect optimization of methods for determining concentrations of antibodies or antigens. Particles coated with an antigen or an antibody are suspended in an aqueous medium where pH and ionic strength are controlled so that the coulomb effect and the van der Waals forces on and exerted by the particles are balanced.

Indirect test for the qualitative and quantitative determination of immunoglobulins, G, A or M in human body fluid utilizing immuoglobulins (IgG, IgA and IgM) chemically coupled to latex carrier particles as the reagent.

Novel immunochemical assay reagents comprising combinations of (A) a carboxyl-containing water-soluble mono-olefinic polymeric compound combined with a hapten or its chemically modified product, or a hapten-supported latex resulting from the chemical linking of the hapten-bound polymeric compound to a polymeric latex, with (B) a hapten antibody, or a hapten antibody-supported carrier; and a method for immunochemically determining haptens by using the aforesaid reagent. This reagent is very stable and can be stored for an extended period of time without degradation. It enables transition from an agglutination inhibited pattern to an agglutinated pattern to be discerned clearly and rapidly with high sensitivity.