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Updated: Jun 2, 2026
Visualization of miniSOG Tagged DNA Repair Proteins in Combination with Electron Spectroscopic Imaging (ESI)
Published on: September 24, 2015
In situ visualization of damaged DNA in human sperm by Raman microspectroscopy
C Mallidis1, J Wistuba, B Bleisteiner
1Centre for Reproductive Medicine and Andrology, University of Münster, Domagkstrasse 11, 48149 Münster, Germany. con.mallidis@ukmuenster.de
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.
