After fixing the cells at room temperature for 15 min with this 4% paraformaldehyde, the cell membrane blisters, do I need to change the fixation temperature to 4°C?

After fixing the cells at room temperature for 15 min with this 4% paraformaldehyde, the cell membrane blisters, do I need to change the fixation temperature to 4°C?

The blistering of cell membrane may be caused by too long fixation time, you can shorten the fixation time appropriately to optimize the fixation result.