title: In situ visualization of damaged DNA in human sperm by Raman microspectroscopy.
abstract: BACKGROUND
  Beyond determining the percentage of damaged sperm, current methods of DNA assessment are of limited clinical utility as they render the sample unusable. We evaluated Raman microspectroscopy, a laser-based non-invasive technique that provides detailed chemical 'fingerprints' of cells and which potentially could be used for nuclear DNA-based sperm selection.
  
  
  METHODS
  Eight healthy donors provided ejaculates. After system optimization, a minimum of 200 air-dried sperm/sample/donor, prior to/and after UVB irradiation, were assessed by two observers. Spectra were analysed by Principal Component, Spectral Angle and Wavelet Analyses.
  
  
  RESULTS
  Spectra provided a chemical map delineating each sperm head region. Principal Component Analysis showed clear separation between spectra from UV-irradiated and untreated samples whilst averaged data identified two regions of interest (1040 and 1400 cm(-1)). Local spectral analysis around the DNA PO(4) backbone peak (1042 cm(-1)), showed that changes in this region were indicative of DNA damage. Wavelet decomposition confirmed both the 1042 cm(-1) shift and a second UVB susceptible region (1400-1600 cm(-1)) corresponding to protein-DNA interactions. No difference was found between observer measurements.
  
  
  CONCLUSIONS
  Raman microspectroscopy can provide accurate and reproducible assessment of sperm DNA structure and the sites and location of damage.
authors.affiliation: Centre for Reproductive Medicine and Andrology, University of Münster, Domagkstrasse 11, 48149 Münster, Germany. con.mallidis@ukmuenster.de
authors.forename: C
authors.initials: C
authors.lastname: Mallidis
authors.forename: J
authors.initials: J
authors.lastname: Wistuba
authors.forename: B
authors.initials: B
authors.lastname: Bleisteiner
authors.forename: O S
authors.initials: OS
authors.lastname: Damm
authors.forename: P
authors.initials: P
authors.lastname: Gross
authors.forename: F
authors.initials: F
authors.lastname: Wübbeling
authors.forename: C
authors.initials: C
authors.lastname: Fallnich
authors.forename: M
authors.initials: M
authors.lastname: Burger
authors.forename: S
authors.initials: S
authors.lastname: Schlatt
mesh_terms: D004247:DNA / Q000648:ultrastructure*; D004249:DNA Damage; D006801:Humans; D008297:Male; D025341:Principal Component Analysis; D013059:Spectrum Analysis, Raman; D013094:Spermatozoa / Q000648:ultrastructure*
chemical_list: D004247:DNA