Hemoglobin precipitation greatly improves 4-methylumbelliferone-based diagnostic assays for lysosomal storage diseases in dried blood spots.

Autor: Oemardien LF; Department of Clinical Genetics, Erasmus MC, Center for Lysosomal and Metabolic Diseases, Rotterdam, The Netherlands., Boer AM, Ruijter GJ, van der Ploeg AT, de Klerk JB, Reuser AJ, Verheijen FW
Jazyk: angličtina
Zdroj: Molecular genetics and metabolism [Mol Genet Metab] 2011 Jan; Vol. 102 (1), pp. 44-8. Date of Electronic Publication: 2010 Sep 26.
DOI: 10.1016/j.ymgme.2010.09.008
Abstrakt: Derivatives of 4-methylumbelliferone (4MU) are favorite substrates for the measurement of lysosomal enzyme activities in a wide variety of cell and tissue specimens. Hydrolysis of these artificial substrates at acidic pH leads to the formation of 4-methylumbelliferone, which is highly fluorescent at a pH above 10. When used for the assay of enzyme activities in dried blood spots the light emission signal can be very low due to the small sample size so that the patient and control ranges are not widely separated. We have investigated the hypothesis that quenching of the fluorescence by hemoglobin leads to appreciable loss of signal and we show that the precipitation of hemoglobin with trichloroacetic acid prior to the measurement of 4-methylumbelliferone increases the height of the output signal up to eight fold. The modified method provides a clear separation of patients' and controls' ranges for ten different lysosomal enzyme assays in dried blood spots, and approaches the conventional leukocyte assays in outcome quality.
(Copyright © 2010 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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