i
Enhanced Stability of Blood Matrices Using a Dried Sample Spot Assay to Measure Human Butyrylcholinesterase Activity and Nerve Agent Adducts
-
6 2 2015
-
-
Source: Anal Chem. 87(11):5723-5729
[PDF-623.99 KB]
Details:
-
Alternative Title:Anal Chem
-
Personal Author:
-
Description:Dried matrix spots are safer to handle and easier to store than wet blood products, but factors such as intra-spot variability and unknown sample volumes have limited their appeal as a sampling format for quantitative analyses. In this work, we introduce a dried spot activity assay for quantifying butyrylcholinesterase (BChE) specific activity which is BChE activity normalized to the total protein content in a sample spot. The method was demonstrated with blood, serum, and plasma spotted on specimen collection devices (cards) which were extracted to measure total protein and BChE activity using a modified Ellman assay. Activity recovered from dried spots was ∼80% of the initial spotted activity for blood and >90% for plasma and serum. Measuring total protein in the sample and calculating specific activity substantially improved quantification and reduced intra-spot variability.|Analyte stability of nerve agent adducts was also evaluated, and the results obtained via BChE-specific activity measurements were confirmed by quantification of BChE adducts using a previously established LC-MS/MS method. The spotted samples were up to 10-times more resistant to degradation compared to unspotted control samples when measuring BChE inhibition by the nerve agents sarin and VX. Using this method, both BChE activity and adducts can be accurately measured from a dried sample spot. This use of a dried sample spot with normalization to total protein is robust, demonstrates decreased intra-spot variability without the need to control for initial sample volume, and enhances analyte stability.
-
Subjects:
-
Keywords:
-
Source:
-
Pubmed Central ID:PMC4517423
-
Document Type:
-
Funding:
-
Volume:87
-
Issue:11
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
