A substance or reactant intended to be used together with a parent IVD to perform a specific function in an assay that is used to evaluate a clinical specimen to determine the genotype for one or multiple blood groups. The blood group systems to be genotyped may include Rhesus (CcDEe), Kell (K, k, Kp^a, Kp^b), Duffy (Fy^a, Fy^b, Fy^x), Kidd (Jk^a, Jk^b), Lewis (Le^a, Le^b), MNS (M, N, S, s, U), Xg (Xg^a), Dombrock (Do^a, Do^b), Colton (Co^a, Co^b), Cartwright (Yt^a, Yt^b), Lutheran (Lu^a, Lu^b) and/or Diego (Di^a, Di^b).