Fast and cheap blood tests
According to this article from Technology Review, U.S. researchers have developed an integrated blood barcode chip which can identify what's in your blood in less than 10 minutes. Instead of going to a lab, having a shot, and waiting for results for a day or two, this new chip will allow physicians to practice sophisticated exams in their offices by using a single drop of your blood. And these tests will be very cheap compared to existing procedures. If this chip becomes widely available, you might one day enter your physician's office and learn a few minutes after that you have a cancer. Of course, such blood chips are a good thing, but they also are frightening. Read more...
You can see above the design of an integrated blood barcode chip (IBBC). This figure depicts "plasma separation from a finger prick of blood by harnessing the Zweifach-Fung effect. Multiple DNA-encoded antibody barcode arrays are patterned within the plasma-skimming channels for in situ protein measurements." (Credit: California Institute of Technology (Caltech) research team)
This blood chip has been developed by Caltech chemistry professor James Heath and his colleagues, and by Leroy Hood, the president and founder of the Institute for Systems Biology in Seattle. Hood is already known for his participation of the invention of the high-speed DNA sequencer that made the Human Genome Project possible.
With other researchers, Heath and Hood have founded a company called Integrated Diagnostics to commercialize this new blood chip. Here are some additional details provided by Xconomy about this startup that will spot tiny cancers in blood (Luke Timmerman, September 26, 2008). The article says that the new company is still keeping a low profile, and doesn't have a website yet.
Let's go back to the Technology Review article to learn about this cheap new chip. "'We decided to make things dirt cheap: it costs a nickel a protein,' Heath says of the current device. Such rapid and cheap tests requiring only a drop of blood should allow doctors to monitor more proteins more frequently, enabling earlier detection of diseases like cancer and better preventive care for the elderly. The new diagnostics should also be more accurate, says Heath. Traditional blood samples sit for hours or even days before the measurement process is completed, allowing plenty of time for them to degrade."
And how this new chip work? It "starts the analysis process with some simple microfluidics. A drop of blood is pulled down a microscale channel by the application of a small external pressure. This first channel branches off into narrower ones, which exclude blood cells and admit the protein-rich blood serum. In typical blood tests, this separation step requires a centrifuge. The narrower channels are patterned with what Heath calls a protein bar code -- lines of DNA bound to antibodies that capture proteins of interest from the serum. After the serum and cells are flushed out, antibodies bound to red fluorescent proteins are flushed in, lighting up captured blood proteins. The protein bar codes can be read under a fluorescent microscope or a gene-chip scanner. The identity of the captured blood proteins can be determined by the location of red lines in the bar code relative to a green fluorescent reference line."
This research work has been accepted by Nature Biotechnology under the title "Integrated barcode chips for rapid, multiplexed analysis of proteins in microliter quantities of blood." The article is available since November 16, 2008 as an advance online publication.
Here is a link to the abstract. "As the tissue that contains the largest representation of the human proteome, blood is the most important fluid for clinical diagnostics. However, although changes of plasma protein profiles reflect physiological or pathological conditions associated with many human diseases, only a handful of plasma proteins are routinely used in clinical tests. Reasons for this include the intrinsic complexity of the plasma proteome, the heterogeneity of human diseases and the rapid degradation of proteins in sampled blood. We report an integrated microfluidic system, the integrated blood barcode chip that can sensitively sample a large panel of protein biomarkers over broad concentration ranges and within 10 min of sample collection. It enables on-chip blood separation and rapid measurement of a panel of plasma proteins from quantities of whole blood as small as those obtained by a finger prick. Our device holds potential for inexpensive, noninvasive and informative clinical diagnoses, particularly in point-of-care settings."
For more information, d the full article is also available (PDF format, 6 pages, 490 KB). The above figure has been extracted from this paper.
Sources: Katherine Bourzac, Technology Review, November 17, 2008; and various websites
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