Comparison of different procedures for the hemato-fluorometric measurement of erythrocyte zinc-protoporphyrin
Louro, M.O.; Lorenzo, M.J.; Tutor, J.C.
Sangre 35(4): 311-315
1990
ISSN/ISBN: 0036-4355 PMID: 2274841 Document Number: 365054
A comparison between procedures for the determination of erythrocyte zinc-protoporphyrin (ZPP) in an AVIV Mod. 206 Haematofluorometer was performed. Initial readings decrease with time, reaching a stability at 6-8 min. This fact cannot be accounted by ZPP photodegradation. High correlation coefficients (r greater than or equal to 0.994) were obtained when values from initial readings were compared with values obtained from readings after ten minutes and with values obtained using saline washed erythrocytes, although in all cases the difference of means were statistically and clinically significant. The use of "ProtoFluor Reagent", which converts haemoglobin to cyanohaemoglobin, led to significantly higher results than those obtained after aeration of the sample, although the correlation between both series of values was also excellent (r = 0.997). No statistically significant differences were found when the ratio sample: ProtoFluor Reagent was changed. These results demonstrate the need for a careful standardization of the operation procedure in the use of the haematofluorometer.