In vitro stability of assayed renin activity in plasma and whole blood
| Autor: | Sally E Green, Frances Short, Ruth Lapworth |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
medicine.medical_specialty
Blood Specimen Collection Chromatography Plasma samples Chemistry Clinical Biochemistry General Medicine Heparin Plasma Plasma renin activity In vitro Endocrinology Internal medicine Renin–angiotensin system Blood plasma Hypertension Renin medicine Humans Edetic Acid medicine.drug Whole blood |
| Zdroj: | Annals of clinical biochemistry. 27 |
| ISSN: | 0004-5632 |
| Popis: | The present procedure recommended by the Supraregional Assay Service (SAS) for processing blood samples for the measurement of plasma renin activity (PRA) is that blood should be collected into tubes containing lithium heparin, centrifuged immediately and the plasma stored at 20°C until despatch to the SAS laboratory. Samples that have not been processed in this way, or those that are sent frozen but thaw in transit are discarded as unsuitable for assay. This causes considerable inconvenience to the patient, clinician and staff of the initiating laboratory. It has been reported':" that PRA is stable if blood samples collected into tubes containing disodium-ethylenediaminetetraacetate (EDTA Na2) are left at room temperature for up to 4 h before separation of plasma from red blood cells. Plasma renin activity is stable in plasma samples stored at 20°C, but the effect of repeated freezing and thawing of plasma on PRA has not been investigated. It was therefore decided to re-examine the stability of PRA in blood collected into lithium heparin tubes and the effect of freezing and thawing plasma to determine whether the stringent recommendations for collecting and processing samples might be relaxed. Duplicate blood samples from 60 hypertensive patients were collected into tubes coated with lithium heparin. One blood sample from each subject was centrifuged immediately and the plasma stored at 20°C until assay. The second sample was either left at room temperature (21°C) for 4h (n = 35) or 24h (n = 25), centrifuged and the plasma frozen at 20°C. Samples from anyone patient were analysed in the same batch. Plasma samples (n = lOS) that had been previously assayed after processing in the recommended way and refrozen immediately were thawed and left at room temperature (21°C) for |
| Databáze: | OpenAIRE |
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