Biovolume calculation and three-dimensional imaging of bovine spermatozoa by digital holography

We show an approach exploiting the capability of optical tweezers to trap and put in rotation bovine spermatozoa flowing into a microfluidic channel. At same time, digital holographic microscopy allows to image the cell in phase-contrast modality for each different angular position, during the rotation. From the collected information about the cell's phasecontrast signature, it is possible to reconstruct the 3D shape of the cell and estimate its volume. The method can open new pathways for rapid measurement of in-vitro cells volume in microfluidic lab-on-a-chip platform, thus having access to the 3D structure of the object avoiding tomographic microscopy. © 2014 OSA.