Figure 1

Principal features of the experimental procedure. A target region of a cell on a Petri dish was positioned underneath the AFM tip through the observation of an inverted optical microscope combined with AFM (a). The AFM tip was then lowered onto the cell and inserted into it, and held for approximately 45 s to allow the tip to bind the cell ingredient containing mRNA with physical absorption. The tip was then lifted off the cell and placed into a PCR tube. To avoid the contamination of nucleic acid, all AFM instruments were treated with DNAZap (Ambion, TX, USA) and then washed with RNase free water extensively. β-actin mRNA expression of five rat VNOF90 cells (b) and two mouse MC3T3-E1 cells (c) was examined as shown in the even numbered lanes. In the negative control (odd numbered lanes), the tip was contacted with media without the insertion of it into the cell.