Abstract: Apparatus and methods to improve the Boyden chamber used in cellular biological measurements, allowing quantitative optical microscopy of biological cells in situ without using fluorescent probes or optical staining. A thin, porous membrane separating top and bottom reservoirs includes an array of precisely positioned micropores pores manufactured using a laser-based photo-machining (ablation) process. The membrane may be composed of polyethylene terephthalate (PET), polycarbonate, polyimide, polyether ether ketone (PEEK), polystyrene, or other appropriate material. The pores formed in the membrane may have diameters in the range of 1 to 15 microns and spaced apart at a distance ranging from 10 to 500 microns. A plurality of upper and lower reservoirs may be provided to form a multi-well plate.