beta-thromboglobulin in antecubital vein blood--the influence of age, sex and blood group.

Samples of blood for estimation of beta-thromboglobulin (B.T.G.) in normal subjects have been obtained both from blood donors at the end of their donation and from other volunteers by standard venepuncture. The former was a satisfactory method in males only. By standard venepuncture females have on average lower values than males and in the pre-menopausal age groups the difference is statistically significant. Mean values vary little up to 59 years after which they rise slowly but steadily. There is no significant difference in the mean B.T.G. values between the ABO blood groups.