2006 Volume 74 Issue 1 Pages 12-18
Microinjection has long been regarded as an unusually difficult method but its potential usefulness has been well understood. In order to overcome its difficulty, a single-cell manipulation supporting robot (SMSR) has recently been developed. SMSR has enabled high throughput microinjection into any type of cell. Its excellent performance was demonstrated by the high success rate of simultaneous introduction of two genes into mouse ES cells. The size of an ES cell is only 20 µm in diameter. With use of a multichannel microelectrode, electrophoretic introduction and automatic positioning of microinjector have been successfully demonstrated. Owing to these studies, single-cell analysis is now recognized as a practical method for the dynamic analysis of functional role of genes, gene expression products, and other molecules in living cells. For instance, the specific role of a protein Sar1p in the trafficking in BY-2 cells could be analyzed by microinjection experiment of a Sar1p dominant negative. Further advancing study is focused on the development of novel electric/electrochemical devices with submicro or nano size and the analytical methods using these devices.