Assays Go Digital
Applied Biocode offers a barcoded, magnetic-bead, high-throughput approach based on digital technology, according to company president, Winston Ho, Ph.D., who was one of the speakers at the “Biodetection Technologies” meeting.
“The motivation for development of our platform was the need to process a large number of tests—up to 1,024—in a single microwell.”
The barcodes the company uses are similar to those found in other commercial operations. The number of permutations of arrangements of the barcode is 2N, so that by increasing the number of wide and narrow bars in a module from 1 to 10, the number of unique identifiers can be easily extended.
The company’s technology employs a permanent digital barcode, which is bonded to the beads using photolithography for greater batch consistency. It is open ended, scalable, and the detection of the signal is accomplished with an LED and a lamp, rather than through the use of lasers and flow cytometers, thus providing greater robustness, according to Dr. Ho.
Because of the elevated accuracy of the barcode classification, a large number of different beads can be loaded in a single microwell. Positive reactions are detected using fluorescence with the dye, such as phycoerythrin, which fluoresces at 575 nm.
By combining digital barcodes with molecular diagnostics, the company has built a polymer bead with the magnetic barcodes encapsulated inside and permanently encoded. This accuracy allows up to 1,024 tests to be combined in a single tube.
Applied Biocode is in collaboration with a number of partners to develop various DNA, RNA, and protein assays. These include IL-2, with a sensitivity down to the pictogram range, MRSA, and a ten-plex panel for cytokines.
GE Global Research (ge.geglobalresearch.com) has developed a lead technology platform for measuring multiple biomarkers in tumor tissues, explained John Burczak, Ph.D., chief scientist for molecular imaging at the company. His team is evaluating methods for the detection of cancerous pathology in tissue samples.
The conventional approach, when suspected malignant tissues are scored, is by a somewhat subjective judgment of the pathologist, who ranks the tissues on a numerical scale according to the degree of malignancy. The decision is frequently controverted by alternative expert opinion, and in some cases by the original evaluator on re-examination.