Compiled by BioPhotonics staff
TEMPE, Ariz. – A new investigative tool that allows scientists to observe DNA, proteins and viruses could make significant
research inroads to improve drug discovery, further studies of host cell-pathogen
interactions and refine analysis of stem-cell differentiation.
The technique, called electrochemical impedance microscopy (EIM),
can peer into single cells and view intracellular processes with clarity, helping
scientists to explore subtle features in basic and applied research. These include
cell adhesion, apoptosis and electroporation, a process that introduces DNA or drugs
into cells. The method builds upon the advantages of an existing technology, electrochemical
impedance spectroscopy (EIS), which applies an AC voltage to an electrode, measuring
the current response as a change in impedance.
EIS allows subtle phenomena that occur at the electrode’s
surface to be imaged, including molecular binding events, and when modified, can
be used to study cell spreading, adhesion, invasion, toxicology, mobility and other
cellular processes. The noninvasive technique also does not require fluorescent
labeling particles or dyes, which often interfere with normal cellular functioning.
Although EIS has proved attractive, it does not provide good spatial
resolution, according to scientists at Arizona State University. EIM, on the other
hand, allows for submicron spatial resolution of biological phenomena. Using specialized
video cameras to record rapid cellular events, the scientists studied apoptosis,
enabling better understanding of its cellular mechanisms, which is critical for
cancer research and the design of cancer therapies. The technique also has made
it possible to observe electroporation, which can be used to insert a molecular
probe to monitor a cell’s interior or to introduce a cell-altering drug or
segment of coding DNA.
Further work will be conducted to refine the label-free, noninvasive
microscopy technique. The research findings appeared in the journal Nature Chemistry,
Jan. 23, 2011 (doi: 10.1038/nchem.961).