Resolution of the WITec Confocal Raman instrument depends upon the wavelength of excitation laser and the Numerical Aperture (NA) of the objective. Currently, there are three wavelengths available for use with the instrument: (1) 488-nm; (2) 514-nm; and (3) 633-nm. MCL offers a number of top quality objectives to choose from, depending upon the requirements of the application. The three most commonly used objectives are the 40X (NA = 0.6), 100X (NA= 0.9), 100X immersion-oil (NA = 1.25) providing lateral resolutions (using 488-nm excitation) of, 488-nm, 325-nm, and 235-nm, respectively.