tailieunhanh - Báo cáo hóa học: " Surface properties of glass micropipettes and their effect on biological studies"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Surface properties of glass micropipettes and their effect on biological studies | Malboubi et al. Nanoscale Research Letters 2011 6 401 http content 6 1 401 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Surface properties of glass micropipettes and their effect on biological studies Majid Malboubi 1 Yuchun Gu2 and Kyle Jiang1 Abstract In this paper an investigation on surface properties of glass micropipettes and their effect on biological applications is reported. Pipettes were pulled under different pulling conditions and the effect of each pulling parameter was analyzed. SEM stereoscopic technique was used to reveal the surface roughness properties of pipette tip and pipette inner wall in 3D. More than 20 pipettes were reconstructed. Pipette heads were split open using focused ion beam FIB milling for access to the inner walls. It is found that surface roughness parameters are strongly related on the tip size. Bigger pipettes have higher average surface roughness and lower developed interfacial area ratio. Furthermore the autocorrelation of roughness model of the inner surface shows that the inner surface does not have any tendency of orientation and is not affected by pulling direction. To investigate the effect of surface roughness properties on biological applications patch-clamping tests were carried out by conventional and FIB-polished pipettes. The results of the experiments show that polished pipettes make significantly better seals. The results of this work are of important reference value for achieving pipettes with desired surface properties and can be used to explain biological phenomenon such as giga-seal formation. Introduction Since Barber 1902 used a glass pipette as an intracellular microelectrode 1 micropipettes have become an essential tool for biological studies. Dozens of pipettes may be used by an individual in a single day. A micropipette works as a bridge between microscopic biological samples and macroscopic measuring devices most often by forming a liquid channel