LAUSR

B iobanking of clinical samples is becoming increasingly important for studying human diseases and is essential for developing effective therapies. Peripheral blood mononuclear cells (PBMC), isolated at different times during disease and therapy, are fundamental for clinically relevant research. However, PBMC are manually isolated from blood with limited standardization of techniques among laboratories worldwide. The procedure requires a high expenditure in terms of the time required and the involvement of experienced personnel to ensure high operational capacity and to reduce pre-analytical variability. Despite the obvious need for a reproducible and automated system that is capable of isolating PBMC for biobanking, only a few pioneering works have been conducted to automate parts of this complex procedure. Here, we compiled, established, and validated a unique robotic system and an automated process that comprises all of the steps required to isolate PBMC, starting with the extraction of cells from the original blood collection tube through to counting and aliquoting the PBMC into cryovials for long-term storage. We sought to develop an automated process that (1) is built on a classical manual density gradient workflow, (2) maintains the quality and quantity of PBMC, and (3) offers advantages in terms of consistency, hands-on time, throughput, sample tracking, and error reduction. Our robotic system is based on five components (Fig. 1A), comprising a Hamilton Microlab STAR Autoload with four 1000-mL and four 5mL pipetting channels equipped with a Tube Twister and barcode scanner, a Hamilton LabElite Integrated I.D. Capper, and a Hettich Rotanta 460 Robotic centrifuge integrated with a Hamilton HMotion plate handler serving as the loading device. All components are enclosed and equipped with high-efficiency particulate air (HEPA) filter hoods and ultraviolet (UV) light options to reduce the risk of sample contamination. With a processing time of 2–3.5 hours and a hands-on time of <15 minutes, up to 12 barcoded primary standard blood collection tubes (e.g., Sarstedt S-Monovette or BD Vacutainer for volumes between 2.7 and 10 mL) are processed in parallel via the workflow described below and presented in Figure 1B (Supplementary Table S1 provides further details regarding the individual processing steps). First, the collection tubes are loaded and registered in the laboratory information management system (LIMS). The caps are removed, and the aliquots are taken for automated