A magnet separates the sandwich complexes from the rest of the sample. The complexes are then heated to release the DNA bar codes, which are then measured by an extremely sensitive detector. Each DNA piece greatly increases the sensitivity of the test and its potential to tell doctors a patient carries the ADDLs.
According to the researchers, BCA is about 1 million times more sensitive than the next best thing ?standard enzyme-linked immunoassays (ELISAs). ELISAs do not have the sensitivity required to detect ADDLs in cerebrospinal fluid.
BCA could eventually be configured to detect hundreds of diseases simultaneously ?with a single procedure, doctors could quickly and inexpensively test a blood sample for any number of ailments. The researchers developed BCA to detect a mere few dozen molecules amongst a sample filled with billions and have already experimented with biomarkers for AIDS and prostate cancer.
This research was supported by both NSF's Engineering Research Centers program and the NSF Office on International Science and Engineering.
Comments from the researchers:
"This study is a major step forward in identifying a routine diagnostic tool for Alzheimer's disease, and it validates our hypothesis that there are many biomarkers for disease that go under the radar of conventional diagnostic tools. The extraordinary sensitivity of the bar code assay has a chance to change the way the medical community thin
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Source:National Science Foundation