Quantitative Label-Free Animal Sperm Imaging by Means of Digital Holographic Microscopy

A digital holographic microscope (DHM) has been employed in the retrieval and analysis of morphological images of bovine's sperm cells. Digital holography is a noncontact technique capable of investigating the shape of the sample without altering its characteristics and has been used for the first time in retrieving quantitative morphological information of sperm cells. Different spermatozoa have been analyzed by means of this technique allowing us to obtain 3-D images with precise topographical details and valuable information about morphological defects, provided with biological considerations. Moreover, by making use of a microfluidic system, the digital holographic technique has been employed to analyze unstained spermatozoa in their natural physiological surroundings. Detailed information on morphological images of spermatozoa acquired by DHM is expected to provide a better understanding of various reproductive pathways, which, in turn, can help in improving infertility management. This could constitute the basis of an alternative method for the zoothecnic industry aimed at the investigation of morphological features and the sorting of the motile sperm cells.