The selection of thin epithelial layers: a method for single cell preparations of very small biopsies from the vocal...

Precancerous lesions in biopsy material very rarely contain more than a thin epithelial layer of atypical cells overlaying stromal parts. This makes it difficult to produce cell monolayers for cytometry from archival material and necessitates a technique which excludes the stromal areas. We have developed a method by which it is possible to separate epithelial layers from the stroma with a thickness of 100-200 microns, using fluorescence microscopy and dissection under a stereo microscope. The stroma can be used as an internal reference in IOD measurements. Our method insures maximum control when dealing with very small lesions of interest (down to 0.02 mm2) that have to be separated from the rest of the biopsy. The method has been applied to normal, dysplastic and cancerous epithelial parts of biopsies of the vocal chords.