Recent biomedical research prefers analysis of homogenous samples obtained from primary cells to cell lines. Moreover, attention is paid to cells of low number but high biological impact, such as signalling centres in embryonic development, stem cells or tumour cells. To localize cells of interest within an organ/tissue, histological sections are widely used. However, the methods of choice for further analysis of such samples are mostly limited to histochemistry, immunohistochemistry and in situ hybridization.