Simultaneous holographic microscopy and Raman spectroscopy monitoring of human spermatozoa photodegradation

Coupling digital holography with high-specific Raman spectroscopy is an attractive means of identifying biochemical changes in cells by both physical topography and spectroscopy. We have used this approach to simultaneously study biochemical and morphological characteristics of human sperm cells irradiated with green laser radiation. Severe spermatozoa variations associated with a topological redistribution of the sample and a gradual decrease in the Raman signal intensity were detected in a label-free configuration. Importantly, at laser fluences where no morphological alterations were detected (30 MJ/cm2 ), high specific spectral variations were monitored to evaluate the cell photodegradation.