scholarly journals Effect of temperature on lysosomal enzyme activity during preparation and storage of dried blood spots

2017 ◽  
Vol 32 (1) ◽  
pp. e22220 ◽  
Author(s):  
Manjunath Supriya ◽  
Tanima De ◽  
Rita Christopher
Keyword(s):  
Enzyme Activity ◽  
Lysosomal Enzyme ◽  
Dried Blood Spots ◽  
Effect Of Temperature ◽  
Lysosomal Enzyme Activity ◽  
Blood Spots ◽  
And Storage

Should phosphatidylethanol be currently analysed using whole blood, dried blood spots or both?

2019 ◽  
Vol 57 (5) ◽  
pp. 617-622 ◽  
Author(s):  
Van Long Nguyen ◽  
Michael Fitzpatrick
Keyword(s):  
Whole Blood ◽  
Blood Cells ◽  
Dried Blood Spots ◽  
Storage Conditions ◽  
Ethanol Metabolism ◽  
Clinical Use ◽  
Blood Spots ◽  
Comparative Review ◽  
And Storage

Abstract Phosphatidylethanol (PEth) are phospholipids produced through non-oxidative ethanol metabolism. They accumulate in red blood cells and have been traditionally analysed in whole blood as potential biomarkers for moderate to long-term alcohol consumption. More recently, their analysis in dried blood spots has been gaining favour, namely, due to the ease in sampling, transport and storage conditions required. This paper aims at providing a short comparative review between analysing PEth in whole blood and dried blood spots and the potential pitfalls that researchers may face when setting up PEth testing for clinical use.

scholarly journals Spectrophotometric Microassay for δ-Aminolevulinate Dehydratase in Dried-Blood Spots as Confirmation for Hereditary Tyrosinemia Type I

2001 ◽  
Vol 47 (8) ◽  
pp. 1424-1429 ◽  
Author(s):  
Andreas Schulze ◽  
David Frommhold ◽  
Georg F Hoffmann ◽  
Ertan Mayatepek
Keyword(s):  
Enzyme Activity ◽  
Neonatal Screening ◽  
Dried Blood Spots ◽  
Confirmatory Test ◽  
Type I ◽  
Screening Programs ◽  
Blood Spots ◽  
Tyrosinemia Type I ◽  
Aminolevulinate Dehydratase ◽  
Hereditary Tyrosinemia

Abstract Background: Hereditary tyrosinemia type I (HT) fulfills the criteria for inclusion in neonatal screening programs, but measurement of tyrosine lacks clinical specificity and quantitative assay of succinylacetone is laborious. We developed a semiquantitative assay based on inhibition of δ-aminolevulinate dehydratase (ALA-D) by succinylacetone. Methods: Preincubation of 3-mm discs from dried-blood spots and reaction of the enzyme with δ-aminolevulinic acid as substrate were performed in microtiter plates. After separation of the supernatant and 10 min of color reaction with modified Ehrlich reagent, the formation of porphobilinogen was measured at 550 nm in a plate reader. Results: The detection limit for succinylacetone was 0.3 μmol/L; imprecision (CV) was <5.5% within-run and 10–16% between-run. Storage of blood spots at ambient temperature for several days led to a significant decrease of ALA-D activity. Enzyme activity was lost in filter cards at 45 °C, but remained stable at 2–37 °C. Enzyme activity was decreased in EDTA blood. The absorbance at 550 nm was 0.221 (± 0.073) in healthy neonates and 0.043–0.100 in 11 patients with HT. All neonates with increased tyrosine (above the 99.5th centile) in neonatal screening (97 of 47 000) had normal results by the new assay. Conclusions: The spectrophotometric microassay for ALA-D is a simple and sensitive test for HT. This represents a basis for further examination of its general reliability as a confirmatory test if tyrosine is found to be increased.

Sign in / Sign up

Export Citation Format

Share Document