Eight-station automatic microtube capper/decapper system for clinical examinations and biological experiments

Abstract Polymerase chain reaction (PCR) testing is effective in diagnosing the novel coronavirus disease (COVID-19). The automation of this process is hampered by a severe lack of compact microtube cappers/decappers that accommodate a wide array of microtubes. To address this issue, we developed an automatic microtube capper/decapper (AMC/D) system, which we call the single-AMC/D (S-AMC/D) because it handles individual tubes one at a time. Subsequently, considering the strong demands of clinical laboratory and biological laboratory personnel, we developed a manually operated microtube equipped with the AMC/D. We also discovered that there exists a significant demand among laboratory automation system developers and automatic pipetting equipment manufacturers for multistation AMC/Ds capable of handling numerous microtube caps simultaneously to increase throughput. In this study, we propose a multistation automatic microtube capper/decapper (M-AMC/D) with improved throughput for automating clinical experiments and bioexperiments that use microtubes. We adopted two design concepts to develop this M-AMC/D: According to the first one, eight microtubes can be opened and closed at one process. According to the second one, eight microtubes can be driven by staggering the timings of their opening and closing operations so that the loads generated by the torques of multiple opening and closing operations are not applied to the drive system or structural system at the same time. Based on the design concepts, we performed the basic design of an eight-station AMC/D (8-AMC/D) with a new driving mechanism using cams and cam followers. The installation space (249 × 93 mm) of this system is approximately 35% of the installation space required for the eight S-AMC/Ds (124 mm × 78 mm × 8 units). Finally, we developed a prototype model of the proposed M-AMC/D and conducted a function confirmation experiment and a verification experiment to improve the throughput. The experimental results of throughput improvement showed that the operation time of the 8-AMC/D was 110.5 s—a significant reduction of 343.3 s (or 75.7%) from the S-AMC/D operation time of 453.9 s. Thus, the effectiveness of the proposed 8-AMC/D was verified. As a result, we successfully developed a groundbreaking device capable of handling, opening, and closing eight microtubes in a single operation. We believe that the proposed system can be used to automate similar tasks in a variety of clinical tests and biological experiments.