We're not requesting any donations. Never donate to any entity who says They're raising resources for us. Hemagglutinin inhibition (Hello) assay: The HI assay assessments for antibodies towards the hemagglutinin of the precise influenza virus utilizing pink blood cells (RBC). Several types of RBCs have been assessed within the HI https://www.dailypioneer.com/2015/state-editions/pre-1995-dq-allotment-report-in-3-months-min.html