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 nDNA based sperm selection. METHODS: 8 healthy donors provided ejaculates. After system optimisation, a minimum of 200 air dried sperm/sample/donor, prior to/and after UV 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 non treated samples whilst averaged data identified two regions of interest (1040 and 1400 cm-1). Local spectral analysis around the DNA PO4 backbone peak (1042 cm-1), showed 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.

@TechReport{MWBDGWFBS11,
  author       = {Mallidis, C. and Wistuba, J. and Bleisteiner, B. and Damm, O. and Groß, P. and Wübbeling, F. and Fallnich, C. and Burger, M. and Schlatt, S.},
  title        = {In situ visualization of damaged DNA in human sperm by Raman microspectroscopy},
  institution  = {WWU Muenster},
  year         = {2011},
  url          = \{/2011/MWBDGWFBS11},
}