Nanosphere Inc. today announced researchers have developed a colorimetric detection capability for its nanoparticle-based molecular detection systems that will further simplify the identification of genomic DNA, RNA and protein targets without the need for traditional signal or target amplification. Findings are published in the July 2004 issue of Nature Biotechnology (available on-line May 30, 2004, www.nature.com/nbt).
Nanosphere researchers evaluated the addition of colorimetric detection to its ClearReadTM technology in the identification of the mecA gene, a biomarker widely associated with clinically challenging methicillin resistant Staphylococcus aureas (MRSA). Among results, researchers observed a green-to-orange color change that detected the presence of the targeted mecA sequence from clinical samples of MRSA. Further, the high detection sensitivity and specificity of the colorimetric assay enabled testing to be performed without using amplification procedures.
"Nanosphere's technology addresses a tremendous unmet need for greater simplicity in molecular testing," said Vijaya Vasista, Nanosphere's Chief Operating Officer. "This colorimetric detection also adds to the flexibility of Nanosphere's platform, as it can be leveraged for the detection of various targets at extremely low concentrations, either visually or in conjunction with Nanosphere's genomic detection instruments."
At the core of Nanosphere's technology, gold nanoparticles are attached to strands of nucleotides complementary to targets of interest, and when a target nucleic acid or protein is present, the nanoparticle probes latch on to the match and provide a strong optical signal indicating the target has been found. The unique hybridization characteristics of gold nanoparticle probes result in sharp melting curves that enable dramatically improved sensitivity and specificity, with the ability to detect specific DNA sequences in highly complex DNA samples.
Nanosphere launched Verigene
Nanosphere also currently has two development contracts with the U.S. government. The first contract, initiated in October 2002 and recently extended, was awarded to Nanosphere from a field of 12,000 applicants to provide its Verigene
Nanosphere, a privately held life sciences company with headquarters in Northbrook, Ill., is developing a universal molecular testing platform that sets a new standard in the improvement of patient care and enhancement of public safety. Nanosphere's platform, that has 1,000 times greater sensitivity and 10,000 times greater specificity than traditional molecular testing systems, addresses the persistent need for simplified molecular testing methods that can quickly and easily detect targeted DNA, RNA and proteins.