%0 Journal Article
%T Atomic force microscopy: a powerful tool for high-resolution imaging of spermatozoa
%A Sunil Kumar
%A Koel Chaudhury
%A Prasenjit Sen
%A Sujoy K Guha
%J Journal of Nanobiotechnology
%D 2005
%I BioMed Central
%R 10.1186/1477-3155-3-9
%X Sperm morphology is regarded as a significant prognostic factor for fertilization and pregnancy [1]. Abnormal sperm morphology is one of the most common factors of male infertility. Morphological changes are also considered to be a potential target in contraceptive development. There is, therefore, an urgent need to analyze the morphological alterations of spermatozoa in their nearly physiological environment in greater detail.Atomic force microscopy (AFM) has opened up new avenues of study in reproductive biology. AFM, invented by Binnig, Quate and Gerber in 1986, has evolved as a powerful imaging technique to obtain nanometer-resolved topographic data images. In brief, the sample surface is raster scanned by a flexible cantilever with a sharp tip at one end. A laser beam focused on the back of the cantilever is bounced off and is detected by a photodiode detector. The ability of this technique to image non-conductive living cells in physiological environment (aqueous solution) in 3D array without elaborate sample preparation or fixing of samples unlike conventional electron microscopy (which requires the cells to be fixed with aldehyde and stained) has made AFM a valuable tool to study various biomolecules [2-4], including sperm cells [5]. AFM imaging in air require cells to be fixed to avoid structural changes caused by drying forces on the cell [6]. But this fixing need not require post fixation like in electron microscopy. Conventional microscopy not only distorts sperm morphology, but is also unable to provide high-resolution 3D images owing to the small size of the spermatozoa. Optical microscopy provides valuable information only if the alterations are gross and of the order of a micron or fraction thereof.AFM provides the advantage of directly observing spermatozoa in their native environment thereby opening the exciting possibility of analyzing their structural and functional aspects at the sub-molecular level. This article provides a review on morphologic
%U http://www.jnanobiotechnology.com/content/3/1/9