title: Diagnosis of HIV-1 infection by near-infrared spectroscopy: analysis using molecular clones of various HIV-1 subtypes.
abstract: BACKGROUND
  Previously, we investigated the possibility of using near-infrared (NIR) spectroscopy for the diagnosis of human immunodeficiency virus type-1 (HIV-1) infection. Here, we further analyze NIR spectra using molecular clones of various HIV-1 subtypes.
  
  
  METHODS
  Culture supernatants of pNL4-3- (HIV-1 molecular clone) or pUC18- (empty vector) transfected 293 T cells were used. In addition, culture supernatants obtained using pBal (HIV-1 subtype B molecular clone) or pIndieC (HIV-1 subtype C molecular clone) were used. Near-infrared radiation (NIR) spectra, obtained using the culture supernatants, were subjected to principal component analysis (PCA) to extract and analyze their properties.
  
  
  RESULTS
  The PCA demonstrated that HIV-1 in medium altered wavelength absorption at around 950 and 1030 nm, suggesting that the HIV-1 altered OH vibration in water. In addition, absorption varied among subtypes at around 950, 1030 and 1060 nm, suggesting that the interaction between HIV-1 and water varies among subtypes.
  
  
  CONCLUSIONS
  These differences in the NIR spectra may make it possible to delineate HIV-1 subtypes spectroscopically.
authors.affiliation: Department of Virology, Center for Infectious Disease Control, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan. sakudo@biken.osaka-u.ac.jp
authors.forename: Akikazu
authors.initials: A
authors.lastname: Sakudo
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Suganuma
authors.forename: Rina
authors.initials: R
authors.lastname: Sakima
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Ikuta
mesh_terms: D003001:Cloning, Molecular / Q000379:methods*; D057809:HEK293 Cells; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification*; D006801:Humans; D025341:Principal Component Analysis; D013055:Spectrophotometry, Infrared / Q000379:methods*