INTRACELLULAR DISTRIBUTION PATTERNS OF ORGANELL SPECIFIC PROTEINS USING IMMUNOHISTOCHEMICAL STAINING OF TISSUE MICRO ARRAYS

Abstract: The knowledge of the human genome sequence, as revealed in the HUGO project, has created exciting new possibilities for biomedical research. The Swedish Human Proteome Resource (HPR) program aims to make use of this information to gain further insight into the human proteome. Recombinant proteins are generated from coding sequences identified from the human genome sequence and used to produce specific antibodies to target proteins. Antibodies are subsequently utilized for functional analysis of the corresponding proteins using tissue micro arrays. The aim of my project was to investigate the possibility of distinguishing characteristic distribution patterns of intracellular proteins in the resolution capacity offered by light microscopy. A map of representative distribution patterns was created using immunohistological staining with commercially available antibodies toward well-characterised proteins in the cell. Such a map could then aid in interpreting the results of immunohistological staining of intracellular proteins using antibodies produced within the Human Proteome Resource program. Proteins manifested in nucleus, nuclear membrane and plasma membrane were clearly visible at the expected location. Proteins manifested in different organelles in the cytoplasm however, showed all a similar staining pattern, making determination of exact protein location uncertain. A possible explanation is the resolution of the light microscope not being sufficient to visualize certain proteins specific to organelles in the cytoplasm. Results may also have been influenced by the choice of secondary antibody, where the strenghtened signal generated by an enzyme labelled polymer may have a negative effect on depiction of details in the image generated.