Agilent Measurement Journal - Issue 3 - 2007 - (Page 23)

Although various biological molecules can be attached to AFM cantilevers, using AFM with large arrays of biological molecules will require advances in hardware and software. Microarrays are typically composed of individual micron-sized spots of discrete chemical identity organized on glass microscope slides. Hundreds or thousands of these spots can be arranged on a typical microarray. The arrays can be reacted with various assay reagents and, with the aid of specialized instrumentation and software, thousands of speciﬁc interactions evaluated. Current microarray technology calls attention to thousands of molecular interactions on the array; it typically does not quantify the forces of interaction between interacting species, nor does it evaluate these interactions at the single-molecule level. By combining AFM with microarray technology, the forces of molecular interaction between array elements and assay reagents can be determined. Figure 7. MAC Mode AFM images of an area of human hair before (left) and after (right) treatment with shampoo. Scan size = 22 µm x 22 µm. Imaging in the cosmetics and hygiene industries In the cosmetics and hygiene industries, the surface of materials such as fabric or human hair is routinely studied before and after applying a cleaning agent. AFM provides a quick way to obtain high-resolution images of material surfaces with little or no sample preparation. Figure 7 shows AFM images of an area of human hair before (left) and after (right) treatment with shampoo. Studies of this type aid in the development of safer, more effective products. This requires an AFM scanning mechanism in a top-down conﬁguration as well as an AFM cantilever afﬁxed to the scanning mechanism in order to permit a large enough space under the sample plate to accommodate a translatable stage for aligning individual microarray elements with the cantilever. Modular AFM systems, such as the Agilent 5500 atomic force microscope, provide ready platforms for future development of microarray capabilities. Conclusion Atomic force microscopy is well on its way to becoming an indispensable measurement method for many life science, pharmaceutical and other bio-related investigations. With continued advances in instrumentation and in situ technologies, AFM will ﬁnd utility in an ever-widening range of emergent biological applications. Looking to the future In the future, manufacturers of AFM instrumentation will be asked to address numerous new challenges, such as the rapid analysis of large microarrays of biological molecules. Microarray technology has made its biggest impact in the areas of gene expression proﬁling and DNA sequence identiﬁcation, but materials other than nucleic acids — including proteins, membranes, cells and small molecules — can also be arrayed and assayed for activity with microarrays. Agilent Measurement Journal 23

Table of Contents Feed for the Digital Edition of Agilent Measurement Journal - Issue 3 - 2007

Applying Ingenuity to the Measurement of Emerging Technologies Contents Emerging Innovations Department Delivering Bigger Benefits by Optimizing Customer Workflows Measuring Material Properties at the Nanoscale Utilizing In Situ Atomic Force Microscopy in Life Science, Pharmaceutical and other Bio-Related Applications WiMAX™: Plotting a New Path to Global Mobility Addressing the Triple Complexity of Triple-Play Networks What Next for Mobile Telephony? Exploring the Inner Workings of Tire-Pressure Monitoring Systems Developing, Assessing and Applying a High-Resolution Thin-Film Magnetic Probe Making Accurate Settling-Time Measurements Using a Vector Network Analyzer Applying Metabolomics Methods to the Study of Bacterial Leaf Blight in Rice Plants Measuring Stream Dynamics with Fiber Optics survey

Agilent Measurement Journal - Issue 3 - 2007

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