Species Identification

Antibodies in Species ID

Introduction of human serum to host animal produces specific antibodies against human serum proteins. Antihuman hemoglobin (Hb) antibodies, and Antihuman glycophorin A (GPA) antibodies

Titrations of Antibodies

Series of dilutions of antiserum are made and each dilution is tested for activity using either precipitation or agglutination methods.

Titer

Reciprocal of the highest dilution giving a positive reaction

Optimal Ag-Ab Binding Conditions

Increasing ionic strength inhibits binding. Proper buffer system is needed. Introduction of polymers decreases solubility and facilitates precipitation.

ABAcard Hematrace

Identifies human hemoglobin. Good sensitivity, responds to aged and degraded samples.

RSID-Blood

Identifies human glycophorin A protein. Sensitive, no cross-reactivity, no high-hook dose effect.

Ouchterlony Assay

Identity: Two lines of precipitate will fuse
Nonidentity: Unrelated antigens, lines will cross but not fuse
Partial Identity: Related but not identical antigens, lines will merge with spur formation

Crossed-over electrophoresis

Positive - sharp precipitate band
False negative when can occur when excess antigen inhibits precipitation