Comparison of manual methods of determination of albumin in human cerebrospinal fluid by the bromcresol green and immuno-precipitation methods.

Simultaneous determinations of albumin concentrations in human cerebrospinal fluid were made by three different manual methods: bromcresol green dye-binding technique of Doumas et al., a modification of the latter with color measurement shortly after the addition of dye as proposed by Ingwersen and Raabo and finally by an immuno-precipitation technique. Results obtained by the immuno-precipitation method correlated significantly with the dye-binding method of Doumas et al., (r = 0.93) and the procedure of Ingmersen and Raabo (r = 0.94). Data from the two dye-binding techniques correlated significantly with one another also (r = 0.98). However, the immuno-precipitation technique gives albumin values lower than the dye-binding procedures. The latter presumably estimates other proteins which can also bind bromcresol green. The data corroborates the conclusions of earlier investigators that immuno-precipitation method is more specific for albumin assays.