scholarly journals Validation of Accuracy-based Amino Acid Reference Materials in Dried-Blood Spots by Tandem Mass Spectrometry for Newborn Screening Assays

1999 ◽  
Vol 45 (8) ◽  
pp. 1269-1277 ◽  
Author(s):  
Donald H Chace ◽  
Barbara W Adam ◽  
S Jay Smith ◽  
J Richard Alexander ◽  
Steven L Hillman ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Amino Acid ◽  
Tandem Mass Spectrometry ◽  
Newborn Screening ◽  
Dried Blood Spots ◽  
Tandem Mass ◽  
Blood Spots ◽  
Amino Acid Contents ◽  
Amino Acid Concentrations

Abstract Background: Advances in technology and the earlier release of newborns from hospitals have pressed the demand for accurate calibration and improved interlaboratory performance for newborn screening tests. As a first step toward standardization of newborn screening aminoacidopathy tests, we have produced six-pool sets of multianalyte dried-blood-spot amino acid reference materials (AARMs) containing predetermined quantities of five amino acids. We describe here the production of the AARMs, validation of their amino acid contents, and characterization of their homogeneity and their stability in storage. Methods: To each of six portions of a pool of washed erythrocytes suspended in serum we added Phe (0–200 mg/L), Leu (0–200 mg/L), Met (0–125 mg/L), Tyr (0–125 mg/L), and Val (0–125 mg/L). Six-pool sets (1300) were prepared, dried, and packaged. We used isotope-dilution mass spectrometry to estimate the endogenous amino acid concentrations of the AARMs and validate their final amino acid concentrations. We used additional tandem mass spectrometry analyses to examine the homogeneity of amino acid distribution in each AARM, and HPLC analyses to evaluate the stability of the amino acid contents of the AARMs. Results: The absolute mean biases across the analytic range for five amino acids were 2.8–9.4%. One-way ANOVAs of the homogeneity results predicted no statistically significant differences in amino acid concentrations within the blood spots or within the pools (P >0.05). Regression slopes (0 ± 0.01) for amino acid concentrations vs storage times and their P values (>0.05) showed no evidence of amino acid degradation at ambient temperatures, 4 °C, or −20 °C during the intervals tested. Conclusion: The validation, homogeneity, and stability of these blood spots support their use as a candidate national reference material for calibration of assays that measure amino acids in dried-blood spots.

Incorporating the measurement of EDTA in dried blood spots (DBS) by tandem mass spectrometry in routine newborn screening

2014 ◽  
Vol 47 (15) ◽  
pp. 144
Author(s):  
Lawrence J. Fisher ◽  
Osama Y. Al-Dirbashi ◽  
Svetlana Ogrel ◽  
Nathan McIntosh ◽  
Michael T. Geraghty ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Newborn Screening ◽  
Dried Blood Spots ◽  
Tandem Mass ◽  
Blood Spots

scholarly journals Tandem Mass Spectrometry for the Direct Assay of Lysosomal Enzymes in Dried Blood Spots: Application to Screening Newborns for Mucopolysaccharidosis I

2008 ◽  
Vol 54 (12) ◽  
pp. 2067-2070 ◽  
Author(s):  
Sophie Blanchard ◽  
Martin Sadilek ◽  
C Ronald Scott ◽  
Frantisek Turecek ◽  
Michael H Gelb
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Newborn Screening ◽  
Lysosomal Enzymes ◽  
Internal Standard ◽  
Dried Blood Spots ◽  
Simple Liquid ◽  
Tandem Mass ◽  
Mucopolysaccharidosis I ◽  
Blood Spots

Abstract Background: Treatments now available for mucopolysaccharidosis I require early detection for optimum therapy. Therefore, we have developed an assay appropriate for newborn screening of the activity of the relevant enzyme, α-L-iduronidase. Methods: We synthesized a new α-L-iduronidase substrate that can be used to assay the enzyme by use of tandem mass spectrometry together with an internal standard or by fluorometry. The assay uses a dried blood spot on a newborn screening card as the enzyme source. The assay protocol uses a simple liquid-liquid extraction step before mass spectrometry. We optimized enzyme reaction conditions and procedures for the assay, including the concentration of substrate, the reaction pH, the incubation time, and mass spectrometer operation. We also assessed inter- and intraassay imprecision. Results: When the assay was tested on dried blood spots, the α-L-iduronidase activity measured for 5 patients with mucopolysaccharidosis I was well below the interval found for 10 randomly chosen newborns. Inter- and intraassay imprecision were <10%. The synthesis of the α-L-iduronidase substrate is practical for use on a scale needed to support newborn screening demands. Conclusions: This newly developed tandem mass spectrometry assay has the potential to be adopted for newborn screening of mucopolysaccharidosis I. This assay has advantages over a previously reported assay also developed in this laboratory and has the potential to be performed in a multiplex fashion to measure several lysosomal enzymes relevant to treatable lysosomal storage diseases.

scholarly journals Tandem Mass Spectrometry for the Direct Assay of Enzymes in Dried Blood Spots: Application to Newborn Screening for Mucopolysaccharidosis II (Hunter Disease)

2007 ◽  
Vol 53 (1) ◽  
pp. 137-140 ◽  
Author(s):  
Ding Wang ◽  
Tim Wood ◽  
Martin Sadilek ◽  
C Ronald Scott ◽  
Frantisek Turecek ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Newborn Screening ◽  
Internal Standard ◽  
Hunter Syndrome ◽  
Dried Blood Spots ◽  
Assay Method ◽  
Tandem Mass ◽  
Mucopolysaccharidosis Ii ◽  
Blood Spots

Abstract Background: A treatment for mucopolysaccharidosis II (Hunter syndrome) has recently become available. Therefore, we developed a high-throughput assay method appropriate for newborn screening for the relevant enzyme, iduronate 2-sulfatase. Methods: We synthesized a new iduronate 2-sulfatase substrate that can be used to assay the enzyme by use of tandem mass spectrometry together with an internal standard. The assay uses a dried blood spot on a newborn screening card as the enzyme source. Results: When the assay was tested on dried blood spots, the iduronate 2-sulfatase activity measured for 13 patients with Hunter syndrome was well below the interval found for 57 randomly chosen newborns. The assay was more sensitive than previously reported iduronate 2-sulfatase assays. Conclusions: This newly developed tandem mass spectrometry assay has the potential to be adopted for newborn screening of Hunter syndrome. This method also has the potential to be carried out in multiplex fashion to assay several different enzymes relevant to lysosomal storage diseases that are assayed in a single infusion into the mass spectrometer.

Influence of hematocrit and localisation of punch in dried blood spots on levels of amino acids and acylcarnitines measured by tandem mass spectrometry

2006 ◽  
Vol 373 (1-2) ◽  
pp. 27-31 ◽  
Author(s):  
Margareta Holub ◽  
Karin Tuschl ◽  
Rene Ratschmann ◽  
Kristina Anna Strnadová ◽  
Adolf Mühl ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Tandem Mass Spectrometry ◽  
Dried Blood Spots ◽  
Tandem Mass ◽  
Blood Spots
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