Research Of Horizontal Micropipette Puller Based On Bluetooth

In recent years, with the development of life science technology, the patch clamptechnique has become an important means of cell electrophysiology research. Atpresent, the research work are carried out in some of our universities and institutes ofbiology laboratory. Patch clamp experiments need two-step drawing glass electrode,the key to success is up to the patch clamp system probe sealing with the cellmembrane by glass electrode. In addition to the experimental cell culture should bereasonable, the shape of the glass microelectrodes, port diameter, impedance as wellas the smoothness of the tip are also important. Micropipette puller is the instrument tomake glass electrodes, it has played a decisive role in characteristics of electrodes. Apowerful, reliable performance, simple operation puller make a very good stimulativeeffect to the development of patch clamp experiments.Now, the micropipette puller domestic manufacturers seldom, start later, productdemand almost depend on foreign imports. In order to make the glass electrodes thatachieve the patch clamp experimental requirements, we produced a two-step levelmicropipette puller successfully refering to the P-97Flaming/Brown MicropipettePuller which was produced by a company called Sutter from the United States. Weused its products to performance test leading the optimal parameters that was greatreference to patch clamp experiment. The new instrument is easy to operate, drawningparameter setting and saving conveniently. It will produce two symmetrical electrodeseach work, has already put into medical school of Wuhan University patch clampexperiments using.This paper first introduced the mechanical structure and control principle of thisnew micropipette puller, details the electrical control hardware circuit and softwaredesign of the whole system. It used the analog PID regulator to achieve the constantpower heating mode; It adopted displacement measurement circuit and electromagnetcontrol circuit to achieve two-step mode as well as to statistically control the first stepof glass pipe heating length. It also had the environment temperature measurementmodule and display module circuit to make the working environment and conditionsshow clearly to the operator.The puller system used PC as the upper computer data sending and receivingterminal, MCU control system as the lower computer terminal, adopted bluetooth torealize data wireless communication between them. Therefore this paper and thenelaborated obviously the bluetooth principle, protocol and typical application models.It also explained the design method for the puller system. The BlueCore4-Externalmodule as the slave device, using MCU’s UART0to send special AT instruction tocomplete the module initialization and data changing with the PC terminal.Then this passage briefly described the method to design application software byLabVIEW, explained the difference and the advantages of each other between virtualinstrument graphical programming method and traditional text programming method.It also simply introduced the front panel design function diagram of the micropipettepuller system PC software interface and so on. Afterwards it detailed that the performance testing experiment about electrodesmaked by the puller system, got lots of data. We found out the glass electrode shape,port diameter and impedance in relation to the parameters setting by micropipettepuller system, listed test result tables under three different drawning length and drawnthe related curve. We got the optimal parameters that was great reference to patchclamp experiment is: the first step heating power is50%, drawning length is2.45mm,cooling delay time is10seconds and the second step heating power is36%.Finally it summarized the shortcomings and the improved method of the currentmicropipette puller system.