In addition to sodium citrate, CTAD tubes contain theophylline, adenosine and dipyridamol. The last three substances inhibit thrombocyte activation. This "stabilisation" of thrombocytes prevents artificial thrombocyte factors coming into contact with the plasma (falsifying the results). CTAD tube should be used for those determinations in which it is very important to avoid release of platelet factors between collection of blood and performance of the test.
