Effect of storage time of pleural effusions on immunocytochemical cell surface analysis of tumor cells.

Abstract To determine how long tumor cells can be stored without losing their immunocytochemical reactivity, five malignant pleural effusions in EDTA-coated tubes were analyzed after different storage times at either 4 degrees C or room temperature. Only minor differences were observed between the cells from the two storage conditions. Though there was a considerable decrease in the number of tumor cells attached to the slides from day 0 to 1, the number of tumor cells was still sufficient to allow their clear detection with the monoclonal antibody HEA-125 even on day 4 of storage in all cases. Therefore, for routine purposes, pleural fluids in EDTA-coated tubes can be stored for at least one day prior to immunocytochemical staining if the cells are gently handled during preparation. Pleural fluid is a richly nutritious medium not only for keeping cells alive but also for preserving their immunoreactivity.