Measurement of mean corpuscular and packed cell volumes with a Coulter cell counter.
A B Carter, P J Crosland-Taylor, J W Stewart · Journal of Clinical Pathology · 1968
THE COLOUR REACTION Optimal conditions for the deve- lopment of the colour are discussed by Giorgio and Plaut (1965) and have been confirmed.Values above 150 mg per litre may be estimated by dilution of a further aliquot of the eluate.Because of the variation of E620 due to interfering brown pigments, values below 15 mg/litre are not reported but the levels found in vitamin B12 deficiency have been reported to be above 50 mg after valine loading, and this was so in nine patients with pernicious anaemia whose urine has been tested using this method.RECOVERIES Recovery of methylmalonic acid from aqueous solutions and from additions to various urine samples by this method is 70-80% (Table ), almost all the loss being in the ether/ethanol extraction stage.Recovery may be improved by increasing the number of extractions.Purity of the extract has been confirmed by thin-layer chromatography.