Ferry, J D Effect of serum volume and time of exposure to gel barrier tubes on results for progesterone by Roche Diagnostics Elecsys 2010. [electronic resource] - Clinical chemistry Sep 1999 - 1574-5 p. digital Publication Type: Letter ISSN: 0009-9147 Subjects--Topical Terms: Blood Specimen Collection--instrumentationFalse Positive ReactionsGelsGlassHumansProgesterone--bloodReagent Kits, Diagnostic