Rapid method for the estimation of plasma haemoglobin levels.

Technical methods FIG. 2. Foetal hepatocytes after four days in culture.x 900.sions centrifuged at 500 r.p.m. for five minutes at 4°C.The packed cells were washed once in the growth medium and centrifuged again before resuspending them in a minimal amount of the growth medium.The liver cells were subsequently cultured after implantation by the method of Zuckerman, Tsiquaye, and Fulton (1967).The cultures were examined by phase-contrast illumina- tion and by fluorescence microscopy after staining with acridine orange.A practically confluent viable monolayer of cells was obtained after 24 hours in culture, and after 48 hours a number of mitoses were observed in the pre- parations (Fig. 1).Cell debris was present in small quan- tities, particularly at the periphery of the culture and after four days the cells were healthy and viable (Fig. 2).By this technique it is regularly possible to obtain at least 32 separation cultures from the cell suspension contained in a single ampoule.It is a pleasure to thank members of the Tissue Bank of the Royal Marsden Hospital.Miss Susan Baker, B.Sc., and Miss LornaDunkley providedexcellent technical assistance.