title: A comprehensive HBV array for the detection of HBV mutants and genotype.
abstract: OBJECTIVE
  To develop a comprehensive hepatitis B virus (HBV) array providing simultaneous analysis of 8 genotypes, 47 mutations of reverse-transcriptase polymerase gene and 18 mutations of S gene.
  
  
  METHODS
  Oligonucleotides corresponding to various HBV-normal and -mutant sequences were spotted onto pre-treated glass slides. Single-stranded templates of the HBV gene fragment were prepared from serum-DNA of HBV-infected patients by 2-staged PCR and subjected to allele-specific arrayed-primer extension with Cy5-dCTP. Fluorescein-labelled products were scanned at 670nm.
  
  
  RESULTS
  Comparative analysis of 100 unrelated samples using the array and a commercial kit, revealed 44 with additional mutations from the array, these were confirmed by sequencing. Analysis of 381 samples from 45 patients during 1-3 years of anti-viral therapy showed improved sensitivity with detection of drug-resistant mutations months before clinical relapse. The lower detection limit was 28 copies/mL.
  
  
  CONCLUSIONS
  The array is better than many existing methods as it provides both mutations and genotype data in a single analysis.
authors.affiliation: Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong.
authors.forename: Kaimin
authors.initials: K
authors.lastname: Chan
authors.forename: Irene
authors.initials: I
authors.lastname: Yam
authors.forename: John
authors.initials: J
authors.lastname: Yuen
authors.forename: Man-Fung
authors.initials: MF
authors.lastname: Yuen
authors.forename: Ching-Lung
authors.initials: CL
authors.lastname: Lai
authors.forename: Graeme J
authors.initials: GJ
authors.lastname: Alexander
authors.forename: Tai-Kwong
authors.initials: TK
authors.lastname: Chan
authors.forename: Vivian
authors.initials: V
authors.lastname: Chan
mesh_terms: D002232:Carbocyanines; D003845:Deoxycytosine Nucleotides; D024882:Drug Resistance, Viral / Q000235:genetics; D005500:Follow-Up Studies; D005838:Genotype; D006509:Hepatitis B / Q000188:drug therapy / Q000235:genetics / Q000821:virology*; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D057230:Limit of Detection; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods; D012194:RNA-Directed DNA Polymerase / Q000235:genetics*; D012680:Sensitivity and Specificity; D014759:Viral Envelope Proteins / Q000235:genetics*
chemical_list: D002232:Carbocyanines; C544355:Cy5-dCTP; D003845:Deoxycytosine Nucleotides; C118669:S envelope protein, hepatitis B virus; D014759:Viral Envelope Proteins; D012194:RNA-Directed DNA Polymerase