The Cellometer instruments are capable of performing concentration, viability and cell size measurements of cultured and primary cell lines as well as perform more complicated cell based assays that are routinely used during the development of cancer immunotherapies. With bright-field and fluorescent platforms, these robust instruments are capable of performing consistent and accurate cell measurements for a large variety of samples. Dual fluorescence-based units (Auto 2000, K2, and Vision) are capable of measuring the concentration and viability of nucleated cells in clinical samples without the need to perform red-blood cell lysis. For isolated or purified cell samples the bright-field trypan blue Cellometers (Mini, Auto 1000, and T4) acquire multiple images, and automatically report the percent viability, cell concentration, and average mean diameter in under 30 seconds. Together these instruments cover every cell counting need that researchers may have in the immunotherapy field.