Definition: if pneumococcal organisms, India ink, and specific antisera are mixed, the antibodies present in the sera will bind to the polysaccharide antigens of the pneumococcal capsule and the capsule will appear more opaque and swollen. This test will identify the organism as being pneumococcal as well as the specific capsular types.
Synonym(s): Neufeld capsular swelling
Synonym(s): capsular precipitation reaction
[Ger. Quellung, swelling]