Measuring forces from the piconewton to millinewton range is of great importance for the study of living systems from a biophysical perspective. The use of flexible micropipettes as highly sensitive force probes has become established in the biophysical community, advancing our understanding of cellular processes and microbial behavior. The micropipette force sensor (MFS) technique relies on measurement of the forces acting on a force-calibrated, hollow glass micropipette by optically detecting its deflections. The MFS technique covers a wide micro- and mesoscopic regime of detectable forces (tens of piconewtons to millinewtons) and sample sizes (micrometers to millimeters), does not require gluing of the sample to the cantilever, and allows simultaneous optical imaging of the sample throughout the experiment. Here, we provide a detailed protocol describing how to manufacture and calibrate the micropipettes, as well as how to successfully design, perform, and troubleshoot MFS experiments. We exemplify our approach using the model nematode Caenorhabditis elegans, but by following this protocol, a wide variety of living samples, ranging from single cells to multicellular aggregates and millimeter-sized organisms, can be studied in vivo, with a force resolution as low as 10 pN. A skilled (under)graduate student can master the technique in ~1–2 months. The whole protocol takes ~1–2 d to finish.

从生物物理学的角度测量从皮微微顿到毫微微顿范围的力对于研究生命系统非常重要。在生物物理学界已经确立了使用挠性微量移液器作为高度灵敏的力探针的方法，这加深了我们对细胞过程和微生物行为的理解。微量移液器力传感器（MFS）技术依靠通过光学检测其偏差来测量作用在经过力校准的中空玻璃微量移液器上的力。MFS技术涵盖了可检测力（数十微微牛顿至毫牛顿）和样品大小（微米至毫米）的广泛的微观和介观范围，不需要将样品胶粘到悬臂，并允许整个样品同时进行光学成像本实验。这里，我们提供了详细的协议，描述了如何制造和校准微量移液器，以及如何成功设计，执行MFS实验以及对MFS实验进行故障排除。我们使用线虫模型来举例说明我们的方法秀丽隐杆线虫，但是通过遵循该协议，可以在体内研究从单细胞到多细胞聚集体和毫米大小的生物的各种各样的活体样品，其力分辨率低至10 pN。一个熟练的（本科）学生可以在大约1-2个月内掌握该技术。整个协议大约需要1-2 d才能完成。