Arrays of Uniform Latex Spheres as Test Objects in Optical Microscopy

Abstract

It is the purpose of this communication to illustrate the utility of regular arrays of uniform high polymer latex spheres (2-D crystals) as resolution test objects for the optical microscope. Such test specimen slides are easily prepared, inexpensive, and can be quite accurately characterized as to size of the spheres which make up the arrays. Through their use it was possible to experimentally verify the validity of the generalized form of Abbe's rule (see Eq. (2)) for bright field microscopy.Similarly, it was possible to demonstrate that resolution in dark field microscopy is equal to and can sometimes surpass performance in bright field. Array test objects also hold great promise in the teaching of microscopy. The importance of proper microscopic technique and the difference between resolution and non-resolution, resolution and detection, and the effect of the wavelength of light on resolution are all easily demonstrated through the use of latex arrays.