2.5. Histomorphological examination
Suspended cells collected by centrifugation every 3 days throughout the culture period were examined for histomorpholog-ical examination. Cell viability was determined by staining the cells using 0.05% acridine orange for 2 min and observing in a fluores-cent microscope (Lieca DM 2500, Switzerland) with the excitationand emission wavelengths at 430 and 490 nm, respectively