Table 1.

Parameters having proven or theoretical influence on the quality of the processed blood component (BC).

Main categories	Main items adding diversity	Level of diversity
Donor dependent parameters (genetically controlled)	Sex/gender Immunogenetic characteristics (blood groups) Natural iso-antibodies …	Two By the thousands (millions if applied also to HLA antigens) Variable
Donor dependent parameters (only partly genetically controlled)	Immunization status Nutrition, metabolism Hygiene and intoxications (therapeutic and recreational drugs, supplements, alcohol, tobacco) Meal; or fast Nycthemeral cycle Genital cycle and periods Outside temperature condition …	Hundreds of influential parameters
Donor independent parameters (BC processing)	Shipping time and temperature Needles, plastics and bags, rotators, automats for collection and intermediate storage Devices for cell separation Working temperature Additives (anticoagulant, solutions, pathogen inactivation, etc.) Filtration steps (meshes, temperature, timing, etc.) Pooling steps Preservation conditions Physical interactions in shelf-life conditions (stacking, shocks, thermic differences, shipping, etc.)	Variable Dozens influential parameters
Patient (recipient, beneficiary) dependent parameters	Blood group Immunization status Matching conditions	By the thousands

Each parameter being independent from the preceding one, diversity is created by the multiplication as opposed to the addition of all. The final diversity goes by the million or more. Not all parameters are equally influential but it clearly appears from the table that one given BC collected by one individual, despite being “standardized” to a norm, is unlikely to be “standard.”