Imaging of microscopic objects is an essential art, especially in life sciences. Digital holographic microscopy is a new imaging technique, which is very advanced when compared to optical microscopy. Digital holographic microscopy does not require any preliminary preparation of the samples and can be used to study live objects. This new type of microscopy is very advanced because it yields a 3D volume image from a single hologram. By combining several images, reconstructed from the same digital hologram, but at different focal planes, an increased depth of field can be obtained, which is vastly superior to the depth of a field achieved with traditional light microscopy.
It is shown that digital holographic microscopy is capable of visualising live cells with dimensions of 5–10 μm without any preliminary preparation. A big advantage of the new technique is that it can be used for dynamic visualisation of live cell deformations to study their interactions with other particles as well as the surrounding environment. The new technique was successfully employed to observe the growth and proliferation of Chlorella vulgaris algae. It was illustrated that digital holographic microscopy can be used for label-free morphology analysis of cells and label-free studies of cell division and migration.