A detailed protocol for the measurement of TGF-beta1 in human blood samples.

Quantification of the multifunctional cytokine Transforming Growth Factor-beta1 (TGF-beta1) in blood samples has aroused increasing interest in recent years, since an abnormal regulation of this cytokine appears to play a key role in the pathogenesis of different diseases, such as autoimmundiseases or malignant tumors. The measurement of TGF-beta1 is complicated by a lot of problems concerning the collection, preparation and handling of blood samples, the platelet contamination, and the TGF-beta1 activation procedure. Here, we recommend detailed instructions for measurement of TGF-beta1 in blood plasma samples which should be followed to exclude the determination of false positive or negative results.