Ultra-compact portable Flow Cytometer dedicated for affordable and accurate CD4+ T-cell and CD4% enumeration in HIV monitoring and patient follow-up The CyFlow® Counter is a fully equipped portable and ultra-compact desktop flow cytometer dedicated for routine CD4 and CD4% counting as well as total lymphocyte and WBC counting. With its small size and ultimate robustness, the CyFlow® Counter is easy to place even in small hospitals and laboratories within remote and resource-poor areas, such as on provincial and district levels, close to the patients. It is the perfect device to replace the larger, more expensive, high-maintenance flow cytometers and CD4 counters for HIV monitoring. The CyFlow® Counter features the revolutionary Partec alignFree™ technology. Difficult and time-consuming optical alignment and laser adjustment, typical of the large conventional systems, are not required with the CyFlow® Counter, the first and only real “plug & play” CD4 counter. This enables the lab to fully concentrate on routine HIV monitoring and AIDS patient follow-up. Installation and set-up time of the CyFlow® Counter is reduced to a minimum. It takes less than 5 minutes to get the first CD4 cell count results in the morning. Therefore, a dramatic reduction of the cost per CD4 count and the overall running cost is achieved. Service, technical support, and maintenance requirements are reduced to a minimum. The CyFlow® Counter runs either on 100-240 V or on 12 V DC power (e.g. on a car battery or solar panels) and therefore, can be independent of the local power grid, making it highly suitable for use in remote places and developing countries.