title: EDTA interference in electrochemiluminescence ACTH assay.
abstract: Background As plasma is the recommended sample type for Roche adrenocorticotropic hormone (ACTH) assay, we evaluated the effect of EDTA concentration on Cobas ACTH assay. Methods Samples containing twofold and fourfold higher concentrations of EDTA were prepared by adding plasma to empty K2EDTA tubes and by making under-filled EDTA tubes. All measurements were performed with four replicates. Results Increased EDTA concentration resulted in a significant decrease in ACTH concentration. Fifty-per cent-filled EDTA tube showed 19% decrease in ACTH concentration and 25% filled EDTA tube showed 50% decrease in ACTH concentration. Conclusion We recommend that inadequately filled EDTA specimens should be rejected when using Cobas ACTH assay.
authors.affiliation: 1 Department of Clinical Biochemistry, Silopi State hospital, Silopi, Şırnak, Turkey.
authors.forename: Burak
authors.initials: B
authors.lastname: Toprak
authors.affiliation: 2 Department of Clinical Biochemistry, Tepecik Teaching and Research Hospital, Izmir, Turkey.
authors.forename: Hulya
authors.initials: H
authors.lastname: Yalcin
authors.affiliation: 2 Department of Clinical Biochemistry, Tepecik Teaching and Research Hospital, Izmir, Turkey.
authors.forename: Elif
authors.initials: E
authors.lastname: Arı
authors.affiliation: 2 Department of Clinical Biochemistry, Tepecik Teaching and Research Hospital, Izmir, Turkey.
authors.forename: Ayfer
authors.initials: A
authors.lastname: Colak
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood*; D016477:Artifacts; D057205:Automation, Laboratory; D001681:Biological Assay / Q000592:standards*; D001800:Blood Specimen Collection / Q000592:standards*; D004492:Edetic Acid / Q000737:chemistry*; D006801:Humans
chemical_list: D000324:Adrenocorticotropic Hormone; D004492:Edetic Acid
keywords: ACTH; EDTA; plasma