The present invention generally relates to systems and methods for counting biomolecules or cells. In certain embodiments, the invention provides a cell counting or biomolecule counting system including: a covered chamber having a known height and configured to hold a suspension of biomolecules or cells in a sample; at least one fluorescent light source connected to at least one fluorescent light beam narrowing device; a bright-field light source connected to a bright-field light beam narrowing device; a microscope objective; a detection device; a fluorescent filter assembly to allow only excitation light to illuminate the sample and allow only emission light from the sample to be imaged by the detection device; and a movable light shutter to block bright-field light during fluorescent detection.