Despite the sophistication and range of contemporary microscopy techniques, many important biological phenomena still elude the precision of even the most sensitive tools. The need for refined imaging methods for fundamental research and biomedical applications related to the study of disease remains acute.
Nongjian (N.J.) Tao and his colleagues at the Biodesign Institute at Arizona State University have pioneered a new technique capable of peering into single cells and even intracellular processes with unprecedented clarity. The method, known as electrochemical impedance microscopy (EIM) may be used to explore subtle features of profound importance for basic and applied research, including cell adhesion, cell death (or apoptosis) and electroporationa process that can be used to introduce DNA or drugs into cells.
This new investigative tool is expected to make significant research inroads, improving drug discovery for diseases like cancer, furthering the study of host cell-pathogen interactions, and refining the analysis of stem cell differentiation.
The group's research appears in today's issue of the journal Nature Chemistry.
As Tao explains, the method builds on the advantages of a powerful existing technology known as electrochemical impedance spectroscopy (EIS). Here, an AC voltage is applied to an electrode and the current response is measured as a change in impedance. (Impedance is defined as opposition to alternating current and extends the idea of electrical resistance to AC circuits.)
In addition to permitting observation of DNA, proteins, viruses and bacteria, EIS allows other subtle phenomena occurring at the electrode's surface to be imaged, including molecular binding events. Modifications of the EIS method have been applied to the study of other cellular processes including cell spreading, adhesion, invasion, toxicology and mobility.
A further attraction of the technique is that unlik
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Arizona State University