A NEW PLASTIC EVACUATED TUBE WITH PLASMA SEPARATOR

A new plastic-walled, evacuated blood collection tube (Terumo Venoject II) with plasma separator was evaluated for characteristics related to the use of plastic in place of glass. Plastic tubes were highly resistant to breakage through handling mishaps or failure during centrifugation. Higher centrifugation speed (13,600g) was well tolerated, and centrifugation times as short as 3 minutes at 13,6009 effectively cleared plasma of cellular components, at high plasma yield. Plastic tubes were nearly completely combustible under incineration conditions commonty used for medical waste, and plastic tubes effectively retained Vacuum during the typical shelf life of evacuated blood collection tubes. Collection of carbamezepine specimens in plastic tubes decreased levels an average of 6.8% compared to a heparinized glass tube control under conditions approximating routine use; levels of other drugs (phenytoin, phenobarbital, valproic acid, theophylline, and cyclosporine) were less significantly affected. This modest decrease appeared to result from a combination of an immediate interaction with the plastic surface of the tubes and a time-dependent interaction with the olefin-based separator. Modest but clear benefits, including reduction in specimen breakage, reduced centrifugation time and reduced solid waste after incineration derive from the use of plastic in place of glass in evacuated brood collection tubes. (C) 1995 Wiley-Liss, Inc.