The development of an acquired haemoglobin abnormality caused by thermal injury.

Alkali denaturation of the haemoglobin derived from burned patients at various intervals from the time of the injury was investigated. A delayed denaturation curve was always found. The involvement of the transfused cells was established by a differential agglutination technique. Red cell populations were fractionated into two portions, one of which was probably enriched in younger cells. This portion was preferentially affected.A starch gel technique yielded a "slow" and a "fast" fraction of haemoglobin with differing denaturation rates, even in normals. The "slow" fraction appeared to be increased quantitatively and qualitatively, if compared with normal blood.