The application of a microwave technique for the preparation of cell blocks from sputum.

Microwaves stimulate diffusion in tissue and affect the proteins and membrane of the cell. These actions can be used to shorten the time required to fix and prepare cell blocks from sputum. The fixative containing ethyl alcohol and polyethylene glycol is particularly suitable for microwave enhanced fixation. Applying a commercially available domestic microwave oven, in which the temperature and power level can be set, cell blocks can be prepared from fresh sputum in 35 min. The microscopical results are of a superior quality because of the microwave-induced homogeneous distribution of the effects of the applied immersion fluids on the cells. The method is very successful for all specimens containing a large amount of mucous. Health hazards for laboratory personnel are nil in this cell blocking method; in contrast to when fresh sputum containing infectious agents is used for smear preparation.