The sequence of cell cycle events is governed by an array of proteins which regulates the essential process of cell division. The present study involved extraction of proteins from interphase and mitotic CHO cells, their purification and characterization by protein profiling and estimation of protein concentration. Protein profiling by SDS PAGE confirmed the presence of proteins unique to mitotic extracts with particular reference to a protein of molecular weight ~ 38 kDa . The study also focused on generating polyclonal antibodies against CHO cytosolic mitotic extract, testing their reactivity and employing them to mediate mitotic inhibition. Inhibition of mitosis was observed in a dose dependent manner. The results of the evaluation of homogeneity of cytosolic protein antigens tested by a combination of precipitation reactions in extracted protein solutions and also in situ whole cells by immunofluorescence confirmed that the reactivity of the antiserum was restricted to protein antigens of cancerous cell lines(CHO, Vero and HeLa) and that extracts from normal cells(lymphocytes) failed to react with the same.