Lab-on-a-Chip Technology Requires Standardization

LOC devices are microchip-size systems, that can prepare and analyze tiny fluid samples with volumes ranging from a few microliters to sub-nanoliters, are envisioned to one day revolutionize how laboratory tasks such as diagnosing diseases are performed.

Physical scientists at the US National Institute of Standards and Technology (NIST; Gaithersburg, MD, USA) have suggested that standardized testing and measurement methods, will enable microelectromechanical systems (MEMS) LOC manufacturers at all stages of production, from processing of raw materials to final rollout of products, to accurately determine important physical characteristics of LOC devices such as dimensions, electrical surface properties, and fluid flow rates and temperatures.

To make the case for testing standards, the scientists have focused on autofluorescence, the background fluorescent glow of an LOC device that can interfere with the analysis of a sample. Multiple factors must be considered in the development of a testing standard for autofluorescence, including the materials used in the device, the measurement methods used to test the device, and how the measurements are interpreted. This material property of microfluidic and nanofluidic devices is of increasing importance due to the growing interest in sensitive fluorescence measurements performed in chips fabricated from plastics

Samuel M. Stavis, PhD, the author of the study, said: "Quality control during LOC device manufacturing may require different tests of autofluorescence throughout the process. There may be one measurement of autofluorescence from the block of plastic that is the base material for a chip, another once the block has been fashioned into the substrate in which the functional components are embedded, and yet another as the final device is completed. To manufacture lab on a chip devices with reliably low autofluorescence, accurate measurements may be needed at each stage."

Dr. Stavis emphasizes that it is important not to confuse testing standards with product standards, and to understand how the former facilitates the latter. He added, "A product standard specifies the technical requirements for a lab-on-a-chip device to be rated as top quality. A testing standard is needed to measure those specifications, as well as to make fair comparisons between competing products." The study was published on June 28, 2012, in the journal Lab on A Chip.

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US National Institute of Standards and Technology