DNA damage has been associated with cases of male infertility and a loss of sperm's ability to swim. Although the association between DNA breaks and infertility requires more research, Elfick says that "it's highly likely that the better the DNA, the better off the sperm will be."

Preliminary tests suggest that the technique does not harm the cells, although Elfick says that more rigorous testing must be done in order to bring the technique into clinical use. His team is hoping to commercialize this and other applications for Raman spectroscopy, including analyzing breast-cancer cells for specific proteins in order to tailor chemotherapy to individual patients.

Michael Morris, a chemist at University of Michigan who uses Raman spectroscopy to analyze bone, says that many investigators are working on clinical applications for the technique. At the level of individual cells, scientists are using Raman spectroscopy to distinguish normal cells from cancerous ones, and to identify specific strains of bacteria, such as those that cause treatment-resistant infections in hospitals. Raman spectroscopy also holds promise as a way of studying disease directly in patients. Researchers such as MIT's Michael Feld are investigating the possibility of using it in conjunction with minimally invasive probes to look for cancer or other disease processes inside patients' tissues. Denny Sakkas, a scientist at Yale University and Molecular Biometrics, has developed a similar technology called spectrophotometry to evaluate the viability of embryos, and is working to expand it to analyze human eggs. Morris suspects that many new applications will emerge, as the technology has a great deal of power for detecting chemical change in small samples.