PROJECT SUMMARY Intracellular cargo transport is a vital and ubiquitous cellular process that occurs in all eukaryotic cells. The research focus of the parent grant is to understand the cargo transport mechanism in the protozoan parasite Toxoplasma gondii. To answer these questions my research group uses a combination of cell biology and biophysical techniques and a huge proportion of the data generated in my laboratory is microscopy based. To date we have used a DeltaVision Elite microscope. However, production of this microscope was discontinued in 2019. Many replacement parts are no longer available. Repair and service of the DeltaVision has become increasingly difficult in the last 12 months. We have experienced significant delays in finding replacement parts, which has led to decreased productivity for members of my research team. In the event that a defective microscope part cannot be replaced, all progress on our research projects would stall. With this equipment supplement, we propose to replace the DeltaVision with a Ti2 system from Nikon that has improved functionality. Briefly, the Nikon system has a customizable stage that will be adapted to include a microfluidics system, facilitating the implementation of new in vitro assays and analysis pipelines. In addition, Ti2 can accommodate both confocal and high-resolution applications at either the time of installation or as future upgrades. The Ti2 has an industry leading field of view and increased acquisition speeds. The 4th generation perfect focus system and the ThermoBoxTM will enable long-term multiday imaging experiments, which are currently not feasible. Our work critically depends on a reliable and serviceable microscope. Purchase of the new Ti2 Nikon system will allow us to continue the progress on understanding the cargo transport mechanisms in T. gondii and expand our repertoire of experimental approaches.