I'm not sure what you mean the cell"
a Pian".
That means the cells are growing on the glass slides? If so I usually use 10% buffered Formalin to fix the slides for 10-15 minutes and it is no different with 4% paraformaldehyde for my endothelial cells. After fixation the fresher the batter for most of immunostaining but you are also able to stock the slides in 70% alcohol for a couple of months.
