title: Assessment of an automated capillary system for Plasmodium vivax microsatellite genotyping.
abstract: BACKGROUND
  Several platforms have been used to generate the primary data for microsatellite analysis of malaria parasite genotypes. Each has relative advantages but share a limitation of being time- and cost-intensive. A commercially available automated capillary gel cartridge system was assessed in the microsatellite analysis of Plasmodium vivax diversity in the Peruvian Amazon.
  
  
  METHODS
  The reproducibility and accuracy of a commercially-available automated capillary system, QIAxcel, was assessed using a sequenced PCR product of 227 base pairs. This product was measured 42 times, then 27 P. vivax samples from Peruvian Amazon subjects were analyzed with this instrument using five informative microsatellites. Results from the QIAxcel system were compared with a Sanger-type sequencing machine, the ABI PRISM(®) 3100 Genetic Analyzer.
  
  
  RESULTS
  Significant differences were seen between the sequenced amplicons and the results from the QIAxcel instrument. Different runs, plates and cartridges yielded significantly different results. Additionally, allele size decreased with each run by 0.045, or 1 bp, every three plates. QIAxcel and ABI PRISM systems differed in giving different values than those obtained by ABI PRISM, and too many (i.e. inaccurate) alleles per locus were also seen with the automated instrument.
  
  
  CONCLUSIONS
  While P. vivax diversity could generally be estimated using an automated capillary gel cartridge system, the data demonstrate that this system is not sufficiently precise for reliably identifying parasite strains via microsatellite analysis. This conclusion reached after systematic analysis was due both to inadequate precision and poor reproducibility in measuring PCR product size.
authors: Malaria Laboratory, Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru. paulonvnv@gmail.com.
authors: Paulo
authors: P
authors: Manrique
authors: Malaria Laboratory, Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru. mhoshi87@gmail.com.
authors: Mari
authors: M
authors: Hoshi
authors: Instituto Nacional de Salud, Lima, Peru. manuelma1@hotmail.com.
authors: Manuel
authors: M
authors: Fasabi
authors: Malaria Laboratory, Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru. oscarnol@hotmail.com.
authors: Oscar
authors: O
authors: Nolasco
authors: Department of International Health, Johns Hopkins School of Public Health, Baltimore, MD, USA. pyori@jhsph.edu.
authors: Pablo
authors: P
authors: Yori
authors: Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, CA, USA. maritza.calderon.s@upch.pe.
authors: Martiza
authors: M
authors: Calderón
authors: Department of International Health, Johns Hopkins School of Public Health, Baltimore, MD, USA. gilmanbob@gmail.com.
authors: Robert H
authors: RH
authors: Gilman
authors: Department of International Health, Johns Hopkins School of Public Health, Baltimore, MD, USA. mkosek@jhmi.edu.
authors: Margaret N
authors: MN
authors: Kosek
authors: Malaria Laboratory, Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru. jvinetz@ucsd.edu.|Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, CA, USA. jvinetz@ucsd.edu.
authors: Joseph M
authors: JM
authors: Vinetz
authors: Malaria Laboratory, Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru. dionigamboa@yahoo.com.|Departamento de Ciencias Celulares y Moleculares, Universidad Peruana Cayetano Heredia, Lima, Peru. dionigamboa@yahoo.com.
authors: Dionicia
authors: D
authors: Gamboa
mesh_terms: D016054:DNA, Protozoan / Q000235:genetics; D006801:Humans; D016780:Malaria, Vivax / Q000453:epidemiology / Q000469:parasitology*; D018895:Microsatellite Repeats / Q000235:genetics*; D017720:Molecular Epidemiology; D058889:Molecular Typing / Q000379:methods*; D010568:Peru / Q000453:epidemiology; D010966:Plasmodium vivax / Q000235:genetics*; D015203:Reproducibility of Results
chemical_list: D016054:DNA, Protozoan