English: This image captures HaCaT cells (an immortalized human keratinocyte line) in the exponential growth phase, showing an estimated 30% to 40% confluence on a 10 cm Petri dish. The cells were cultured at 37 ℃, 5% CO2 in DMEM supplemented with 10% FBS and displayed the characteristic polygonal, adherent morphology typical of healthy epithelial cells. The visualization was achieved using Phase Contrast Microscopy on a Nikon Eclipse Ts2 Inverted Microscope, utilizing a 10×/0.25 Ph1 objective for a 100× total magnification. The image was acquired through digiscoping (taking a photo through the microscope eyepiece) using a Samsung A55 smartphone camera.