We are currently replacing our use of TIBC with Transferrin and will report an Fe/TRFN ratio to replace % saturation. We are still debating whether to back calculate the TIBC and the % saturation as well. There was a good review by Beilby in Australia a few years back on this problem: Beilby J, et al. Transferrin index: an alternative method for calculating the iron saturation of transferrin. Clin Chem. 1992 Oct;38(10):2078-81. PMID: 1394993; UI: 93008960. and a fair number of other papers I found in my Medline search -- maurice green, phd, facb clinical chemist stanford hospital palo alto, ca 94305-5627 [log in to unmask] %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%