Turkon, HakanToprak, BurakYalcin, HulyaColak, AyferOzturk, Nurinnisa2025-01-272025-01-2720160007-50271943-7730https://doi.org/10.1093/labmed/lmw027https://hdl.handle.net/20.500.12428/23664Objective: To investigate the effect of temperature and protease inhibitor on adrenocorticotrophin (ACTH) stability. Methods: We collected blood specimens from 10 donors into K3 EDTA (ethylenediaminetetraacetic acid) and K3 EDTA + aprotinin tubes. Plasma specimens were held at room temperature and at 2 degrees C to 8 degrees C for 0, 2, 4, 8, 24, and 72 hours. ACTH concentrations in 4 storage conditions were compared with repeated-measures analysis of variance (ANOVA) at each time point. Results: ACTH concentrations substantially decreased after a 72-hour time period. At the 72nd hour, standard EDTA tubes and EDTA + aprotinin tubes stored at 4 degrees C showed the optimal stability. EDTA + aprotinin tubes stored at room temperature performed more strongly than standard EDTA tubes stored at room temperature. Conclusion: Our results show that refrigerated storage is more effective than protease inhibitor addition to maintain ACTH stability. We recommend using aprotinin tubes, especially for specimens standing at room temperature.eninfo:eu-repo/semantics/openAccessACTHaprotininstabilityproteasespreanalytical phasetemperatureArticle47427928210.1093/labmed/lmw027Q4WOS:0003886109000052-s2.0-8504093944827593170Q3