sfh as produced are shown in table 1 perhaps the greatest concern in producing stroma free hemoglobin besides contamination is the rigorous removal of membrane phospholipid components phospholipid is extremely difficult to measure on a routine basis so the simpler total phosphate assay was used although quite sensitive it does not discriminate the source of the phosphate intracellular enzymes constitute a second group of red cell contaminants and it is not clear whether removal of all red cell enzymes from the final product is even desirable in view of their antioxidant activities u201c units u201d of sfh collected in this way can be stored frozen indefinitely and shipped either to a central processing facility much as plasma processing is carried out in some locations or pooled locally for quality control testing another advantage of the proposed system is that it can drastically reduce costs at the present time all collected blood is subjected to expensive viral testing which is the largest single cost of blood collection using the new system units can be pooled before testing which greatly reduces the overall cost haemonetics estimates that the cost of collection of a unit of blood is 18 of which 15 is for viral testing this cost could be reduced by a factor of 10 for tests done on 10 unit pools for example blood collected in this way may.