Sripad Ram

My research interests revolve around fundamental immunological problems.  Presently, I am involved in the project related to structure-function studies of the human neonatal Fc receptor, FcRn and its role in intracellular trafficking of IgGs and immune complexes at blood tissue barriers.


My research work heavily uses live-cell imaging approaches. Towards this end, I have been developing (as part of my doctoral and postdoctoral work) a variety of tools and technologies for imaging the intracellular trafficking pathways in live cells in 2D/3D at single molecule resolution. The following is a brief list of the past and present work.



FcRn Biology

Intracellular trafficking pathways of IgGs in endothelial cells (2007)


Live cell imaging of lysosomal delivery of FcRn in endothelial cells (2009)




Single molecule microscopy


Single molecule localization and tracking


2D Localization accuracy problem (2004)


3D Localization accuracy problem and depth discrimination in optical microscopes (2005)


Overcoming the depth discrimination problem by simultaneous multifocal plane imaging (2007)


High accuracy 3D single quantum dot tracking in live cells (2008)


Improved 2D/3D localization accuracy using dual objective imaging configuration (2009)





Beyond’s Rayleigh’s criterion— a new resolution measure for optical microscopes (2006)


3D resolution in optical microscopy (2009)


Comparison of 3D resolution capability for different microscope modalities (2009)


Resolution in 3D in multifocal plane microscopy (2008)



Multifocal plane microscopy (MUM)


Simultaneous multifocal plane imaging for 3D visualization of complex intracellular dynamics (2004)


3D Imaging of novel exocytic pathways in live cells (2007)


3D single-molecule tracking of QD-IgG endocytosis in human endothelial cells (2008)


Dual objective multifocal plane microscopy (2009)


Resolving point sources in 3D using multifocal plane microscopy (2009)



Statistical Image Processing


Performance analysis of optical microscopes—a rigorous stochastic approach (2006)







1. Xavier Michalet and Shimon Weiss, “Photon statistics to boost microscopy resolution'', Proceedings of the National Academy of Sciences, 103, 4797-4798, 2006 [full-text].


2. Rajendrani Mukhopadhyay, “Multifocal plane imaging reveals exocytosis dynamics: Meeting News - 51st Annual Meeting of the Biophysical Society'', Analytical Chemistry, 79, 3958, 2007 [full-text].


3. Hong-Wu Shen and Ai-Ming Yu, “New analytical technologies for biological discovery”, Bioanalysis, 2(2), 181-184 [full-text].