Development of a microfluidic setup for the isolation and imaging of immune cells: Towards cell separation at the microliter scale

Specialised cells in the blood play an important role in controlling the immune responses. Thus, these cells are also valuable for the diagnosis and treatment of diseases such as autoimmune disorders and cancer. Trace-less Affinity Cell Selection technology, also known as Fab-TACS technology, is a new approach to precisely isolate specific immune cells from blood samples. Currently, this technology is used in a device called Fabian, which resembles a cassette with a capacity of 60 ml. For diagnostic purposes, however, the sample size must be reduced to a few microliters. For this purpose, a stand-alone setup for the control of a microfluidic cartridge was developed and a sequence for the implementation of the TACS technology was designed and characterized. As the combination of cell purification and subsequent cell counting in a single device can streamline workflows and save time, we also integrated an analysis platform for cell counting into the setup. Instead of using two separate devices, isolated samples can be counted immediately after isolation without interruption. This platform was initially tested with latex particles that were passed through the detection channel of the microfluidic cartridge. The functionality of the developed program sequence and cell counting was successfully demonstrated in verification experiments.