title: Quantitative ultramicrotest for newborn screening of galactosemia in Cuba.
abstract: To describe a simple, rapid, quantitative ultramicrotest (UMTEST) based on the fluorometric method introduced by Fujimura et al. adapted to an Ultra Micro Analytic System (SUMA) for the detection of total galactose (GAL) in dried blood specimens.
  
  
  
  The assay uses 3 mm discs of dried blood on Whatman 903 filter paper and small volumes of each reagent. A methanol/acetone/water solution is used for deproteination, and a specially designed 96-well polystyrene opaque ultramicroplates, with a maximum capacity of 30 μL per well, are used for the reading.
  
  
  
  The UMTEST GAL is completed in 2 h, with measuring range of 0.28-3.92 mmol/L. The intra- and inter-assay coefficients of variation were 2.3%-8.9% and 6.8%-11.1%, respectively, depending on the total GAL concentrations. Percentage recovery ranged from 97.7% to 103%. Limit of detection and limit of quantitation were 0.06 and 0.16 mmol/L, respectively. The mean GAL concentration, in 2510 dried blood samples from the National Neonatal Screening Program was 0.23 mmol/L. Our assay showed high concordance correlations with the commercially available ICN Immuno-Chem™ GAL-MW EA kit.
  
  
  
  The analytical performance characteristics of this assay is suitable for mass newborn screening of galactosemia in Cuba.
authors.affiliation: Department of Neonatal Screening, Immunoassay Center, 134 Street and 25 Avenue, P.O. Box 6653, Cubanacán, Playa, Havana, Cuba.
authors.forename: Amarilys
authors.initials: A
authors.lastname: Frómeta
authors.forename: Ernesto Carlos González
authors.initials: EC
authors.lastname: Reyes
authors.forename: Elisa
authors.initials: E
authors.lastname: Castells
authors.forename: Yileidis
authors.initials: Y
authors.lastname: Tejeda
authors.forename: Pedro
authors.initials: P
authors.lastname: Almenares
authors.forename: Pedro L
authors.initials: PL
authors.lastname: Pérez
mesh_terms: D003462:Cuba; D005470:Fluorometry / Q000379:methods; D005693:Galactosemias / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D007231:Infant, Newborn / Q000097:blood*; D008832:Microchemistry; D015997:Neonatal Screening / Q000379:methods*; D012015:Reference Standards; D015203:Reproducibility of Results