1. The problem statement, all variables and given/known data Your molecular biology lab studies proteins, and you're frustrated because your microscopes can't quite resolve crystallized proteins. A sales rep touts the advantages of an expensive microscope using 200-nm ultraviolet light, saying you'll be able to resolve structures less than half the size that's resolvable with your optical microscopes. Is the sales rep correct? no yes 2. Relevant equations Rayleigh criterion slit: Θmin = λ/a circular aperture: Θmin = 1.22λ/D X-ray diffraction: 2dsinΘ = mλ 3. The attempt at a solution I looked up the wavelength ranges of visible light and found 390nm to 700nm. I also found the average size of a protein to be 531 angstroms or 5.31x10^-8 m. I also heard that you can resolve an object as small as one fourth of the wavelength from somewhere, is this true (can't find anything in the book or online anywhere on this point)? So I thought the answer is the sales rep is correct because the protein length is larger than the wavelengths of visible light. Is this correct thinking? There is not really enough given in the problem to use the equations, so I am led to believe there is some other information I missed somewhere. Thank you.