Forum for Science, Industry and Business

Developing tools for reliable ’gene chip’ measurements

Microarrays, sometimes called "gene chip" devices, enable researchers to monitor the activities of thousands of genes from a single tissue sample simultaneously, identifying patterns that may be novel indicators of disease status. But generating consistent, verifiable results is difficult because of a lack of standards to validate these analyses, scientists from the National Institute of Standards and Technology (NIST) and collaborators warn in the May 20 online issue of Clinical Chemistry.

Microarrays are keychain-sized devices with as many as several million tiny spots, each of which examines genes of interest simultaneously using minute sample volumes. This highly sensitive technology is relatively new, and standard procedures to ensure the reliability and comparability of results are only beginning to emerge. For instance, results can change as a result of differences in how tissues are collected and processed; variations in how the molecules are counted, attached to substrates and labeled for detection; deviations from recommended protocols by lab personnel; and malfunctioning or miscalibrated equipment. Such variations need to be controlled before this technology can be used reliably in clinical settings and in devices requiring regulatory approval, according to the paper.

As a first step toward addressing reliability issues, a consortium co-led by NIST and industry is developing standards that will satisfy needs identified at a 2003 workshop. At the workshop, organized and hosted by NIST, leaders in the microarray field from industry, government and universities recommended the development of a well-characterized set of ribonucleic acid (RNA) molecules whose identity and concentration are known. RNA is an important product of gene activity. Users will be able to validate the results of gene chip analyses by adding such a reference material to their samples and comparing the measured values to what would be expected for them. Such a reference material also will enable technology developers and researchers to assess the performance of their assays.

Laura Ost | NIST
Further information:
http://www.nist.gov/

Im Focus: Virus multiplication in 3D

Vaccinia viruses serve as a vaccine against human smallpox and as the basis of new cancer therapies. Two studies now provide fascinating insights into their unusual propagation strategy at the atomic level.

For viruses to multiply, they usually need the support of the cells they infect. In many cases, only in their host’s nucleus can they find the machines,...

Im Focus: Cheers! Maxwell's electromagnetism extended to smaller scales

More than one hundred and fifty years have passed since the publication of James Clerk Maxwell's "A Dynamical Theory of the Electromagnetic Field" (1865). What would our lives be without this publication?

It is difficult to imagine, as this treatise revolutionized our fundamental understanding of electric fields, magnetic fields, and light. The twenty original...

Im Focus: Highly charged ion paves the way towards new physics

In a joint experimental and theoretical work performed at the Heidelberg Max Planck Institute for Nuclear Physics, an international team of physicists detected for the first time an orbital crossing in the highly charged ion Pr⁹⁺. Optical spectra were recorded employing an electron beam ion trap and analysed with the aid of atomic structure calculations. A proposed nHz-wide transition has been identified and its energy was determined with high precision. Theory predicts a very high sensitivity to new physics and extremely low susceptibility to external perturbations for this “clock line” making it a unique candidate for proposed precision studies.

Laser spectroscopy of neutral atoms and singly charged ions has reached astonishing precision by merit of a chain of technological advances during the past...

Im Focus: Ultrafast stimulated emission microscopy of single nanocrystals in Science

The ability to investigate the dynamics of single particle at the nano-scale and femtosecond level remained an unfathomed dream for years. It was not until the dawn of the 21st century that nanotechnology and femtoscience gradually merged together and the first ultrafast microscopy of individual quantum dots (QDs) and molecules was accomplished.

Ultrafast microscopy studies entirely rely on detecting nanoparticles or single molecules with luminescence techniques, which require efficient emitters to...

Im Focus: How to induce magnetism in graphene

Graphene, a two-dimensional structure made of carbon, is a material with excellent mechanical, electronic and optical properties. However, it did not seem suitable for magnetic applications. Together with international partners, Empa researchers have now succeeded in synthesizing a unique nanographene predicted in the 1970s, which conclusively demonstrates that carbon in very specific forms has magnetic properties that could permit future spintronic applications. The results have just been published in the renowned journal Nature Nanotechnology.

Depending on the shape and orientation of their edges, graphene nanostructures (also known as nanographenes) can have very different properties – for example,...