The use of a versatile specimen holder to prepare cultured cells for scanning electron microscopy

Cells from a human esophageal carcinoma cell line characterized by abundant microvilli and extensive lateral processes were grown on glass coverslips and processed for scanning electron microscopy. In order to reduce possible artifacts related to movement the cultured cells were fixed directly in situ at 37 degrees C and transported for subsequent processing in a specially designed carrier. During dehydration and critical point drying, the cultures were confined in a versatile holder that avoided accidental air drying and required only small volumes of reagents. Flattening of the superficial microvilli on all cells and of processes on mitotic cells was prevented. Extensive fracture of the lateral processes was reduced. Despite the absence of a washing step, debris was minimal and cells of high quality were observed.