A widely applicable plasma renin activity assay by LC-MS/MS with offline solid phase extraction. (May 2014)

• Record Type: Journal Article
• Authors: Owen, Laura J; Adaway, Joanne; Morris, Karen; Lockhart, Stephen; Keevil, Brian G
• Is Part Of: Annals of clinical biochemistry. Volume 51:Number 3(2014:May)
• Page Start: 409
• Page End: 411
• Publication Date: 2014-05
• Subjects: Renin activity -- solid phase extraction -- LC-MS/MS; Clinical chemistry -- Periodicals; Clinical biochemistry -- Periodicals; 616.075
• DOI: 10.1177/0004563214524558
• Languages: English
• ISSNs: 0004-5632

Abstract

Background: The measurement of plasma renin activity using LC-MS/MS is an attractive alternative to radioimmunoassay techniques. A published method for renin activity by LC-MS/MS uses equipment that is not available in all LC-MS/MS laboratories. Here, we present an offline modification to allow users of LC-MS/MS to perform this analysis without specialist equipment. Methods: Samples were prepared in duplicate and incubated for 6.5 h and 24 h. Solid phase extraction was performed offline using Waters Oasis MAX ion-exchange 96-well plate. A method comparison was performed between this assay and a previously published assay using on-line solid phase extraction. Results: The offline method for plasma rennin activity gave similar results to the on-line method across the concentration range. Analytical performance was also found to be comparable and the use of a 24 h incubation for low samples was also deemed unnecessary. Discussion: The method described is an acceptable alternative to a previously published assay which does not require the use of highly specialist equipment and will be applicable to the majority of LC-MS/MS users.