Controllable Fabrication of Small-Size Holding Pipets for the Nondestructive Manipulation of Suspended Living Single Cells br

The capture and manipulation of single cells are an important premise and basis for intracellular delivery, which provides abundant molecular and omics information for bio-medical development. However, for intracellular delivery of cargosinto/from small-size suspended living single cells, the capture methods are limited by the lack of small-size holding pipets, poor cell activity, and the low spatial accuracy of intracellular delivery. To solve these problems, a method for the controllable fabrication of small-size holding pipets was proposed. A simple, homemademicroforge instrument including an imaging device was built to cut and melt the glass capillary tip by controlling the heat production of a nichrome wire. The controllable fabrication of small-sizeholding pipets was realized by observing the fabrication process in real time. Combined with an electroosmotic drive system and amicromanipulation system with high spatial resolution, the holding pipet achieved the active capture, movement, and sampling ofsuspended living single cells. Moreover, solid-phase microextraction was performed on captured single pheochromocytoma cells, and the extracted dopamine was successfully detected using an electrochemical method. The homemade microforge instrumentovercame the limitations of traditional microforges, resulting in holding pipets that were sufficiently small for small-size suspended single living cells (5-30 mu m). This proactive capture method overcame the shortcomings of existing methods to achieve the multiangle, high-precision manipulation of single cells, thereby allowing the intracellular delivery of small-size single cells in suspension with high spatiotemporal resolution