Optimized pregelatinized starch technique for cell block preparation in cell cultures

•We optimized the pregelatinized starch technique for cell block preparation.•We discovered a new method for cell block preparation based on cell suspension.•We applied the new method for cell block preparation in cultured cells.

The aim of the present study was to optimize the pregelatinized starch technique for cell block preparation and apply this approach in cultured cells of all types of growing forms, suspension and adherent. In order to evenly mix the starch powder and the cell suspension, we crafted a special plastic dropper. To prove the effectiveness of this optimized technique we used different cell lines, NCI-H69, NCI-H345, HCT-116, SKBR3 and MDA-MB-231. The morphology features, immunocytochemistry (ICC) and fluorescent/chromogenic in-situ hybridization (FISH/CISH) on the cell block sections were evaluated. The morphology features, the ICC and ISH results of cell block sections prepared by the new method were satisfactory comparing with the results obtained in biopsies, the gold standard test for this kind of analysis. The most attractive advantage of our optimized pregelatinized starch technique is that this new method is based on cell suspensions instead of cell sediment, so with our technique every section will contain cells due to the even distribution of the starch powder and the cells forming a homogeneous cell block. To the authors' knowledge, this is the first description on cell block preparation based on cell suspension.