Comparison of Preanalytical Sample Stability between Serum and Ethylenediaminetetraacetic Acid Plasma for the Measurement of Biological Analytes
10.15263/jlmqa.2020.42.3.140
- Author:
Jiwon LEE
1
;
Kibeom JEON
;
Taekha LEE
;
Jisoo LEE
;
Miyoung KIM
;
Han-Sung KIM
;
Young Kyung LEE
;
Hee Jung KANG
Author Information
1. Department of Laboratory Medicine, Hallym University Sacred Heart Hospital, Anyang, Korea
- Publication Type:Original Article
- From:Journal of Laboratory Medicine and Quality Assurance
2020;42(3):140-149
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
Background:In this study, we aim to examine the effects of pre-analytical factors such as specimen type (serum or plasma), collection and storage conditions, and time, on the results of chemiluminescence immunoassay.
Methods:Blood samples were collected from 10 individuals and aliquoted into two sets of K3-ethylenediaminetetraacetic acid (EDTA) and serumseparating tubes (SST) each, for plasma and serum collection, respectively.For all the samples, one set of tubes was centrifuged within 1 hour and other set was centrifuged after 4 hours, followed by cell separation.Chemiluminescence assay was performed for adrenocorticotropic hormone (ACTH), parathyroid hormone (PTH), osteocalcin, C-telopeptide, and insulin at 0, 6, 24, and 48 hours after centrifugation; all the samples were assayed in duplicate. The samples were stored at 4℃ before the assay.
Results:The results obtained showed that the levels detected in plasmas were more consistent and stable as compared to serum. After a 6-hour storage at 4℃, a significant decrease was observed in the levels of ACTH and osteocalcin in plasma and serum; whereas, PTH and C-telopeptide levels were stable in plasma but decreased significantly in serum. Insulin levels in serum showed a decrease after a 6-hour storage while the levels in plasma were found to be stable until 24-hour storage. Serum samples separated after 4 hours showed a significant decrease in all hormone levels, while C-telopeptide and insulin levels were stable in plasma samples separated after 4 hours.
Conclusions:The results were found to be more stable in plasma samples from K3-EDTA tubes as compared to serum samples from SST in the measurement of unstable biological analytes. These results suggest that K3-EDTA tubes are preferable in the specimen collection for assaying biological analytes.
