Method of functionalizing human red blood cells with antibody

A method of purifying antibodies in a solid phase antibody screening assay, to produce dense functionalized indicator cells which can be used as a component of an assay that will indicate a presence or an absence of antibodies or antigens, comprising:

• coating a predetermined antigen to an affinity column, said predetermined antigen being one of A, B, AB and MNS antigens;
• introducing human plasma into said affinity column, such that antibodies disposed in said human plasma attach to said predetermined antigen;
• purifying said antibodies using immunoaffinity chromatography, such that said purified antibodies remain and other undesired antibodies are removed;
• exposing said purified antibodies to red blood cells, such that said purified antibodies bind with and coat said red blood cells;
• and
• forming indicator cells by exposing said coated red blood cells to additional antibodies that have a specificity for said purified antibodies, such that said additional antibodies attach to said purified antibodies and coat said red blood cells.