Project Summary Flow cytometry is a specialized technology that characterizes cells on a single-cell basis and is heavily used in the fields of immunology, infectious diseases and cancer biology. As the technology has advanced, the multiplexing capability has markedly expanded allowing for more markers to be examined simultaneously. These advances have increased the complexity of experimental design and of the expertise required to appropriately analyze and detect potential artifacts hidden in the resulting data. Advanced training is critical to allow these technologies to be appropriately implemented in resource-limited settings where exposure to scientists and mentors with the requisite expertise is limited. Although complete mastery can take years, the practical and theoretical tools needed to achieve competency can be taught in a relatively short workshop. The African Flow Cytometry Workshop has been held biennially since 2005 in Cape Town, South Africa, with the aim of enhancing both the theoretical and technical flow cytometry knowledge of African immunologists so that this cutting-edge technology can be applied to critical studies being conducted on the continent. This technology has unique capabilities to help address scientific questions of particular relevance in Africa given the high prevalence of disease caused by the three major global pathogens, HIV, tuberculosis and malaria. As flow cytometry instruments with greater capabilities have become more available in Africa, the number of scientists needing this advanced knowledge has also increased. Training opportunities that exist for African investigators remain very limited and can be very costly. The African Flow Cytometry Workshop is structured over five full days and consists of a combination of lectures and hands-on tutorials with homework assigned each evening and an initial and final exam. Attendance is limited to 20 participants, to ensure appropriate interaction between faculty and students and to facilitate peer-to-peer interactions. We have conducted eight previous workshops and this experience has demonstrated the ongoing need for this type of training as well as shown successful outcomes for many prior participants (Nemes, et al., Cytometry A, 2016). As in prior workshops, the selection process is conducted in a thoughtful way in order to choose participants across geographic regions in Africa who are likely to apply their training and train others in their home laboratory. In a survey we conducted of prior workshop participants, almost 90% of respondents reported having trained peers at their home institution after the workshop, often by adapting teaching materials from the workshop. In an effort to perpetuate the training, we have incorporated a strategy to invite select high- achieving past participants to join the workshop faculty, which has served to deepen their understanding of flow cytometry and provide them with leadership training. The workshop training is theref...