Automatic microtube capper/decapper system for clinical examinations and biological experiments

Abstract Polymerase chain reaction (PCR) testing is an effective testing method for diagnosing infectious diseases, and it has been the primary testing method during the novel coronavirus disease (COVID-19) pandemic. PCR tests (from specimen collection to result acquisition) involve a pretreatment process, ribonucleic acid extraction, and real-time PCR testing. From the perspective of infection and contamination risks, there is significance in automating the pretreatment process, where centrifuge tubes, cryopreservation tubes, and microtubes are used. Many automated systems have been designed for centrifuge tubes with screw-type caps; however, few systems have been designed for microtubes with press-type caps. Capper/decapper systems for press-type caps have been proposed; however, there are no small microtube cappers that are compatible with a wide range of microtubes. Thus, in this study, we developed a microtube capper/decapper system that can be used with a wide variety of microtubes. First, to clarify the required specifications for the microtube capper/decapper system, the shapes and opening/closing forces of 15 types of microtubes from 10 manufactures were measured. Then, conceptual, basic, and control system design processes were performed based on the identified requirements. Finally, a prototype model of the proposed microtube capper/decapper system was developed, and verification experiments were performed. The results confirmed that the proposed system can open and close the caps of 15 different types microtubes. Thus, the proposed system can be used in the pretreatment process of PCR tests. We also believe that the proposed system can be used to automate similar tasks in a wide range of clinical examinations and biological experiments.