Electron microscopic analysis of the microtubular structure of HEp-2 cells

Abstract

The HEp-2 cell line was first established by Moore, et al. and today it serves as a widely used subject for a large variety of microbiological and cell-biological experiments. A tubular structure of unknown origin and function has been described first in virally infected, and later in uninfected HEp-2 cells. However, this tubular structure has not been further analyzed. We performed transmission (TEM) and whole cell mount electron microscopic studies of monolayer HEp-2 cells to morphologically describe the structure and relate it to other organelles of the cell.For embedding, HEp-2 cells were grown on glass coverslips in Eagle's minimal essential medium. 24 hours after passage, three types of procedures were carried out: (1) The cells were fixed with 2.5% glutaraldehyde in 0.14 M Na-cacodylate buffer. (2) The cells were treated for 10 min. with Hank's solution containing 0.2% Brij-58 and 2.5% glutaraldehyde. Fixation was completed with 2.5% glutaraldehyde in 0.14 M Na-cacodylate. (3) Cells were treated with 0.2% Brij-58 in Hank’s solution for 10 min. Subsequently, they were fixed with 2.5% glutaraldehyde in 0.14 M Na-cacodylate.