Instability of corticotropin during long-term storage-myth or reality?

Jacquelien J. Hillebrand*, Li Zhou, Marilee A. Marcinkus, Maria Datwyler, Susan H. Gawel, Frans Martens, Gerard J. Davis, Annemieke C. Heijboer

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Objectives: Corticotropin is notorious for its instability. Whereas several studies have investigated its short-term stability in plasma following venous blood sampling, studies on long-term stability are lacking. Here we investigated the long-term storage stability of corticotropin in ethylenediaminetetraacetic acid containing plasma. Methods: Specimens from healthy volunteers (neat, spiked) were stored in polypropylene microcentrifuge tubes with socket screw-caps at-20 °C and-70 °C for up to one and a half years. Corticotropin in plasma was measured using an Abbott research only immunoassay. Separately, specimens from patients were collected during diagnostic routine testing and stored in polystyrene tubes with push-caps at-20 °C for up to 6 years. In these samples corticotropin hormone was measured using the Diasorin corticotropin immunoassay. Results: Storage of specimens at-20 °C or-70 °C for up to one and a half years showed minimal changes (<11%) in corticotropin levels, while storage of patient samples at-20 °C for up to 6 years showed a significant (54%) reduction in corticotropin levels. Conclusions: Corticotropin levels are stable in plasma when stored at-20 °C for one and a half years using the Abbott research only assay, but with longer storage time a significant reduction in corticotropin levels can be expected. Once specimens are stored for future corticotropin measurements, one should consider storage time, storage temperature and assay differences.

Original languageEnglish
Article numberA187
Pages (from-to)60-65
Number of pages6
JournalClinical Chemistry and Laboratory Medicine
Issue number1
Early online date2021
Publication statusPublished - 1 Jan 2022

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