In developing nations, rural areas, and even one’s own home, limited access to expensive equipment and trained medical professionals can impede the diagnosis and treatment of disease. Many qualitative tests that provide a simple “yes” or “no” answer (like an at-home pregnancy test) have been optimized for use in these resource-limited settings. But few quantitative tests—those able to measure the precise concentration of biomolecules, not just their presence or absence—can be done outside of a laboratory or clinical setting. By leveraging their discovery of the robustness of “digital,” or single-molecule quantitative assays, researchers at the California Institute of Technology (Caltech) have demonstrated a method for using a lab-on-a-chip device and a cell phone to determine a concentration of molecules, such as HIV RNA molecules, in a sample. This digital approach can consistently provide accurate quantitative information despite changes in timing, temperature, and lighting conditions, a capability not previously possible using traditional measurements.
Posts Tagged ‘tools’
University of Washington engineers and NanoFacture, a Bellevue, Wash., company, have created a device that can extract human DNA from fluid samples in a simpler, more efficient and environmentally friendly way than conventional methods.
Conventional methods use a centrifuge to spin and separate DNA molecules or strain them from a fluid sample with a micro-filter, but these processes take 20 to 30 minutes to complete and can require excessive toxic chemicals.
UW engineers designed microscopic probes that dip into a fluid sample – saliva, sputum or blood – and apply an electric field within the liquid. That draws particles to concentrate around the surface of the tiny probe. Larger particles hit the tip and swerve away, but DNA-sized molecules stick to the probe and are trapped on the surface. It takes two or three minutes to separate and purify DNA using this technology.
Read the full story on the UW website.
In a feat of technology tweaking that would rival MacGyver, a team of researchers from the University of California, Davis has transformed everyday iPhones into medical-quality imaging and chemical detection devices. With materials that cost about as much as a typical app, the decked-out smartphones are able to use their heightened senses to perform detailed microscopy and spectroscopy. The team will present their findings at the Optical Society’s (OSA) Annual Meeting, Frontiers in Optics (FiO) 2011, taking place in San Jose, Calif. Oct. 16-20.
The enhanced iPhones could help doctors and nurses diagnose blood diseases in developing nations where many hospitals and rural clinics have limited or no access to laboratory equipment. In addition to bringing new sensing capabilities where they are needed most, the modified phones are also able transmit the real-time data to colleagues around the globe for further analysis and diagnosis.
“Field workers could put a blood sample on a slide, take a picture, and send it to specialists to analyze,” says Sebastian Wachsmann-Hogiu, a physicist with UC Davis’ Department of Pathology and Laboratory Medicine and the Center for Biophotonics, Science and Technology, and lead author of the research to be presented at FiO.
Researchers have discovered a method for simultaneously visualizing gene number and protein expression in individual cells. The fluorescence microscopy technique could permit a detailed analysis of the relationship between gene status and expression of the corresponding protein in cells and tissues, and bring a clearer understanding of cancer and other complex diseases, according to researchers who led the study.
The new technique is called the fluorescent in situ gene protein assay. It combines traditional fluorescent in situ hybridization (FISH) with the in situ proximity ligation assay, which is capable of resolving individual protein molecules.