To determine the best resolution of a confocal microscope using 500 nm light, we use the formula for resolution limit, also known as the Abbe diffraction limit: d = λ / (2NA), where d is the resolution, λ is the wavelength of light used, and NA is the numerical aperture of the objective lens. Assuming a commonly used numerical aperture for confocal microscopes is around 1.4, we calculate:
d = 500 nm / (2 × 1.4) = 500 nm / 2.8 ≈ 178.57 nm
Therefore, the best resolution is approximately 180 nm.