title: Genotyping of α-thalassemias by the colorimetric nanogold probes.
abstract: BACKGROUND
  The novel colorimetric nanogold probe was created to genotype subgroups of the mostly found α-thalassemias. They are α-thalassemia 1 (SEA and THAI deletion) and α-thalassemia 2 (3.7-kb and 4.2-kb deletion).
  
  
  METHODS
  The genotyping was performed by two-steps hybridizations. First step was hybridization of target DNA with the nanogold mixed probes of either α-thalassemia 1 or α-thalassemia 2. No hybridization in both reactions showing blue color indicated absence of abnormal genes causing these α-thalassemias. Positive reaction showing either red or purple color was further analyzed in second hybridization with the nanogold single probe. Positive of α-thalassemia 1 was genotyped with the single probes of both SEA and THAI deletion while those of α-thalassemia 2 were genotyped with both 3.7-kb and 4.2-kb deletion.
  
  
  RESULTS
  Genotypic potency of the nanogold mixed and single probes was evaluated using both known diagnosed and suspected clinical samples. The results by naked eye were consistence with those analyzed by standard agarose gel electrophoresis.
  
  
  CONCLUSIONS
  Potency of the colorimetric nanogold α-thalassemia probes was accurate, precise, sensitive, specific, simple, cheap and field applicable. Color reaction was simply visualized by naked eye. This development is an example of colorimetric molecular diagnosis which can be applied in any genetic detection.
authors.affiliation: Clinical Microscopy, Faculty of Medical Technology, Mahidol University; Medical Technology, Faculty of Allied Health Science, Thammasat University.
authors.forename: Sirinart
authors.initials: S
authors.lastname: Chomean
authors.affiliation: Clinical Microscopy, Faculty of Medical Technology, Mahidol University.
authors.forename: Nantawan
authors.initials: N
authors.lastname: Wangmaung
authors.affiliation: Biomedical Engineering, Faculty of Engineering, Mahidol University.
authors.forename: Pornpimol
authors.initials: P
authors.lastname: Sritongkham
authors.affiliation: Clinical Chemistry, Faculty of Medical Technology, Mahidol University.
authors.forename: Chamras
authors.initials: C
authors.lastname: Promptmas
authors.affiliation: Clinical Microscopy, Faculty of Medical Technology, Mahidol University. Electronic address: wanida.itt@mahidol.ac.th.
authors.forename: Wanida
authors.initials: W
authors.lastname: Ittarat
mesh_terms: D003124:Colorimetry / Q000379:methods; D015342:DNA Probes / Q000235:genetics*; D018390:Gene Targeting / Q000379:methods; D005838:Genotype; D006046:Gold; D006801:Humans; D053768:Metal Nanoparticles; D017085:alpha-Thalassemia / Q000175:diagnosis / Q000235:genetics*
chemical_list: D015342:DNA Probes; D006046:Gold
keywords: gold nanoparticles; nanogold probe; thalassemia genotyping; α-thalassemias