A method for identification of viral particles by intracellular counting and segmentation of viral particles in an image, comprising: providing transmission electron microscope (TEM) images, acquired with an electron microscope, having a plurality of objects depicted therein, the objects relating to viral particles and other particles that have elliptical shapes and the images showing cells infected with viral particles and treated with different siRNA treatments; the images, examined in the transmission electron microscope, were captured by a digital camera as digital images; defining a maximum radius and a minimum radius of elliptical objects as an allowable radius range in the image; finding elliptical objects in the image and determining a maximum and minimum radius of the elliptical objects; discarding objects with radial ranges outside the allowable radial range; segmenting each object in the image by applying a rotation invariant and angular invariant analysis computing a radial density profile from the center of each object and removing the mean intensity to compensate for different brightness levels in the different images; plotting the radial density profiles of the viral particles in a linear vector space (LVS) so that a first cluster and a second cluster of the viral particles are shown, the first cluster representing empty viral shells and the second cluster representing mature viral particles; individually counting viral particles plotted in the previous step; depicting the mean radial density profiles for the types of siRNA treated viral particles in the first cluster; depicting the mean radial density profiles for the same types of siRNA treated viral particles in the second cluster; and analyzing morphological/structural changes of the viral particles in the clusters plotted in the LVS to discriminate structural differences between the siRNA treated viral particles when exposed to the siRNA treatments. providing transmission electron microscope (TEM) images, acquired with an electron microscope, having a plurality of objects depicted therein, the objects relating to viral particles and other particles that have elliptical shapes and the images showing cells infected with viral particles and treated with different siRNA treatments; the images, examined in the transmission electron microscope, were captured by a digital camera as digital images; defining a maximum radius and a minimum radius of elliptical objects as an allowable radius range in the image; finding elliptical objects in the image and determining a maximum and minimum radius of the elliptical objects; discarding objects with radial ranges outside the allowable radial range; segmenting each object in the image by applying a rotation invariant and angular invariant analysis computing a radial density profile from the center of each object and removing the mean intensity to compensate for different brightness levels in the different images; plotting the radial density profiles of the viral particles in a linear vector space (LVS) so that a first cluster and a second cluster of the viral particles are shown, the first cluster representing empty viral shells and the second cluster representing mature viral particles; individually counting viral particles plotted in the previous step; depicting the mean radial density profiles for the types of siRNA treated viral particles in the first cluster; depicting the mean radial density profiles for the same types of siRNA treated viral particles in the second cluster; and analyzing morphological/structural changes of the viral particles in the clusters plotted in the LVS to discriminate structural differences between the siRNA treated viral particles when exposed to the siRNA treatments. <EOS>