Adsorption of pregnanediol-3 alpha-glucuronide by plastics and glass.

Radioactive pregnanediol-3 alpha-glucuronide at low concentration was found to bind to a number of common laboratory materials. Adsorption was greatest with polypropylene and unsilanised glass tubes. The presence of 0.1% gelatine reduced adsorption, except in polyethylene insert vials. Adsorption of pregnanediol-3 alpha-glucuronide may present a problem in radioimmunoassay studies.