Low-volume liquid handling capabilities in bioanalytical workflows can dramatically improve sample processing efficiency and reduce reagent costs, yet many commercial nanoliter liquid handlers cost tens of thousands of dollars or more. We have successfully adapted a low-cost and open-source commercial pipetting robot, the Opentrons OT-1, to accurately aspirate and dispense nanoliter volumes. Based on fluorescence measurements, the modified OT-1 was able to reproducibly transfer 50 nL of water with less than 3% measurement error and 5% coefficient of variation (CV). For 15 nL transfers, the volume measurements indicated less than 4% error and 4% CV. We applied this platform to the preparation of low-nanogram proteomic samples for liquid chromatography–mass spectrometry analysis, demonstrating that the modified OT-1 is an effective platform for nanoliter liquid handling. At a total materials cost of less than $6000, including the commercial liquid handler and all modifications, this system is also far less expensive than other platforms with similar capabilities, placing automated nanoliter handling within reach of a far broader scientific community.

生物分析工作流程中的小容量液体处理能力可以显着提高样品处理效率并降低试剂成本，但许多商业纳升液体处理器的成本高达数万美元或更多。我们已经成功地改造了低成本和开源的商用移液机器人 Opentrons OT-1，以准确地吸取和分配纳升体积。基于荧光测量，改进的 OT-1 能够以小于 3% 的测量误差和 5% 的变异系数 (CV) 可重复地转移 50 nL 的水。对于 15 nL 转移，体积测量表明误差小于 4%，CV 小于 4%。我们将该平台应用于制备用于液相色谱-质谱分析的低纳克蛋白质组学样品，证明修改后的 OT-1 是纳升液体处理的有效平台。该系统的总材料成本不到 6000 美元，包括商业液体处理器和所有修改，也比其他具有类似功能的平台便宜得多，将自动化纳升处理置于更广泛的科学界范围内。