# A fluorescence microscope with an objective lens of numerical aperture (NA) 1.5 is used with light of wavelength (λ) 600 nanometers. The lateral resolution limit of this microscope, rounded off to the nearest integer, is _________ nanometers.

**A fluorescence microscope with an objective lens of numerical aperture (NA) 1.5 is used with light of wavelength (λ) 600 nanometers. The lateral resolution limit of this microscope, rounded off to the nearest integer, is _________ nanometers.**

## Answer

**Answer:** 200 nanometers

\textbf{Explanation:} The viable count is calculated by multiplying the colony-forming units (CFUs) by the dilution factor. In this case: 400 \times 10^4 = 4,000,000 \text{ CFU/g} which is equivalent to 4 million CFU/g.