Influence of separator gel in Sarstedt S-Monovette® serum tubes on various therapeutic drugs, hormones, and proteins

► Separator gel for Sarstedt blood collection tubes was tested for influence on 10 common analytes. ► For each analyte 50 samples were compared with and without gel on the day of phlebotomy and on 3 consecutive days. ► The gel was found not to have statistically significant influence on the day of phlebotomy. ► Later on a few minor significant differences appeared but most remained clinical insignificant (85%).