Immunochemical Quantitation of Proteins in Single Cells

Abstract

Abstract An immunochemical method for the quantitative determination of specific soluble proteins in individual erythrocytes has been described. Application of the method revealed: 1. From 0.5 to 0.9 per cent of the normal adult erythrocytes studied contained small amounts of γ-chains, from 2.5 to 12.5 µµg. as hemoglobin per cell. 2. In cord blood of normal infants of 38 weeks’ gestation, significant numbers of erythrocytes were found which contained either γ-chains or β-chains or both, independently of carbonic anhydrase B. 3. Once initiated within a given erythrocyte, β-chain synthesis in that cell rapidly approached adult rates. Derepression of carbonic anhydrase B synthesis was independent of derepression of hemoglobin synthesis, and in fetal cells which contained carbonic anhydrase B the amount found was well below that of most adult erythrocytes. 4. In 4 patients homozygous for hemoglobin S and in 2 persons heterozygous for thalassemia, an increase in F hemoglobin was associated with an increase in γ-chain content of individual erythrocytes as well as an increase in the number of erythrocytes containing γ-chains; in 2 patients homozygous for thalassemia, an unusual distribution of cells with increased γ-chain content was observed.