Comparative HI testing of international reference and national standard sera
Information supplied by NIBSC in 2001 indicated their international standard reference contained 320 IU per ampoule.
The serum can be reconstituted in PBS. A suitable volume of PBS would be 2 mL, which would give 4 IU in the 25 µL test sample. Refer to instructions provided by the manufacturer.
Use the standard HI test described in this section to determine the titre of the international reference standard and the national standard.
Test both samples in triplicate on the same microwell plate.
Carry out a series of at least three tests on different days.