For holographic biopsy purposes, holograms of biological tissue samples have been recorded in vitro to establish the possibility of differentiating tissues on the holograms. With the use of specific absorbing dyes for staining tissues, the contrast has been improved. On the holograms, tissue architecture has been observed in the cortex of the kidney. Isolated epithelial cells could be seen with a distinct nucleus. Two distinct layers of the gray matter in the human brain have been differentiated. Finally, the case of human ovary carcinoma, the differentiation of putatively normal areas and the cancerous lesion has been evidenced and a submillimetric localization of the lesion could be done. Thus, it has been shown that tissue differentiation on holograms is possible, so that holographic biopsy can be used as a diagnostic aid. The use of an endoscope to perform holographic biopsy would provide the surgeon or physician with a new minimal-invasive quick diagnostic method allowing in situ examination of tissues when conventional biopsy is difficult or even impossible. In the near future, the development of an endoscope for holographic biopsy should lead to clinical investigation in early cancer detection. Prior to measurements on tissues, the recording material (silver-halide) has been evaluated to determine the display and processing parameters in order to obtain the best possible results. The resolution has been estimated below 2.8 ?m with a diffraction efficiency of 20%, in the tissue recording configuration.