QUALITY CONTROL & STANDARDIZATION OF AHG
Quality control of reagent in blood bank is known as serological control or sero-control which is a known positive control that can be used in the same way as patients serum. It provides an effective control for the test system and reagents in antiglobulin. Sero-control is a mixture of stabilized lgG antibodies that react positively with all human red cells.
Quality control need to be specified and requirement can be set standards to be laid down by the authority example FDA Quality surveillance
However, quality control for anti human globulin reagent, animal immunization must be carried out, the most common animal used for the production of AHG reagent is rabbit but large scale production can be achieved by immunization of goat. It is preferable to use young animal. Anti human globulin reagent with anti-D coated cells will be titrated with cells for reactivity and with uncoated red cells for specificity.
The standardization of AHG is carried out by preliminary test on AHG which is done by preparation of sensitized O+ red cells and check with cells and non sensitized O+ red cells check with cells: O+ red cell + Anti-D (lgG) suspended in saline.
Everyday or every week we can prepare test: AHG + check cell give positive reaction and AHG + non sensitized RBC give negative reaction.
Secondary test on AHG for quality control is done by standard anti-D which is used as a source of lgG antibody. This anti-D should have a saline titration 1:32 or 1:64 and coombs titration about 1:512 or 1:1024. Test should be done at 370C for 30 minutes.
All the negative tube should be tested by anti human globulin.