The Guava EasyCyte Plus microcapillary flow cytometry system is a compact high throughput system that provides absolute cell counts, 6 parameters (4 fluorescent colors, 2 light scatter), and a blue laser for access to commonly used fluorescent dyes. The 4th color option, combined with the built-in 96-well autosampler, allows researchers to obtain even more data while performing more complex biological studies such as white blood cell phenotyping, cell signaling, cytokine production, activation marker analysis, and multiplex compound screening. Monitoring the interplay of up to four different biological mechanisms simultaneously shortens the number of iterations for any one experiment and comes that much closer to mimicking complex biological responses. The system runs turnkey assays for cell counts/viability, apoptosis, cell cycle, and more, and the near infrared 4th color option expands the information received from any one well, making it much easier to simultaneously monitor for both extracellular and intracellular events as they may relate to changes in immune function.