SpringerOpen Newsletter

Receive periodic news and updates relating to SpringerOpen.

Open Access Nano Express

Surface properties of glass micropipettes and their effect on biological studies

Majid Malboubi1*, Yuchun Gu2 and Kyle Jiang1*

Author Affiliations

1 School of Mechanical Engineering, The University of Birmingham, Edgbaston, Birmingham, B15 2TT UK

2 IMM, Peking University, 5 Yiheyuan Road Beijing, 100871 China

For all author emails, please log on.

Nanoscale Research Letters 2011, 6:401  doi:10.1186/1556-276X-6-401

Published: 31 May 2011

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.