Confocal Raman micro-spectroscopy for rapid and label-free detection of maleic acid-induced variations in human sperm.

Confocal Raman microspectroscopy is a valuable analytical tool in biological and medical research, allowing the detection of sample variations without external labels or extensive preparation. To determine whether this method can assess the effect of maleic acid on sperm, we prepared human sperm samples incubated in different concentrations of maleic acid, after which Raman spectra from the various regions of sperm cells were recorded. Following the maleic acid treatment, Raman spectra indicated significant changes. Combined with other means, we found that the structures and chemical compositions of sperm membranes were damaged, and even the sperm DNA was damaged by the incorporation of maleic acid. Thus, this technique can be used for detection and identification of maleic acid-induced changes in human sperm at a molecular level. Although this particular application of Raman microspectroscopy still requires further validation, it has potentially promise as a diagnostic tool for reproductive medicine.