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

Abstract Polymerase chain reaction (PCR) testing was widely used for diagnosing infectious diseases, particularly during the novel coronavirus disease (COVID-19) pandemic. The automation of this process has been limited 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, recognizing that microtube handling is a fundamental operation not only in PCR testing but also in various clinical examinations and biological experiments, and considering the strong demands of clinical laboratory and biological laboratory personnel, we developed a manually operated microtube equipped with the AMC/D. We also identified 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 mm × 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 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. The proposed device enables simultaneous handling, opening, and closing of eight microtubes in a compact and efficient configuration. Although initially motivated by the urgent demand for PCR testing during the pandemic, the proposed system addresses a fundamental challenge in laboratory automation involving press-type microtubes and is applicable to a broad range of laboratory procedures involving microtubes.