Platelets in Biology and Pathology

had been inflated to midway between systolic and diastolic blood pressures.Total protein was estimated by the rechnicon SMA 12/60 biuret method which had a within-batch coefficient of variation of 1 1%.ETR determinations (Mincey et al., 1974) were performed in duplicate and had a within-batch coefficient of variation of 1-4%.The results are shown in the Figure .Although venous stasis can increase serum total thyroxine concentration it has no significant effect on the ETR or on a free thyroxine index (Judd et al., 1975) because these latter methods have a 'built- in' adjustment for changes in protein binding.It is reassuring to know that the avoidance of stasis when collecting blood although ideal, is not essential for an accurate ETR.