at Nanosphere, Inc. today reported unprecedented benefits
in the company's technology for the medical analysis
of human DNA.
Nanosphere's nanoparticle-based technology allows
for rapid, highly-sensitive and specific Single Nucleotide
Polymorphism (SNP) genotyping, which is the direct
detection of a particular gene and the extent to which
it is normal or mutated. The technology, reported
in the February 2005 (Volume 33, Number 2), issue
of Nucleic Acids Research, allows detection of a SNP
in an unknown genotype with a greater than 99 percent
confidence threshold and can be used with human DNA
obtained from samples as small as a drop of blood.
Importantly, the technology eliminates the need for
costly, time and labor intensive gene amplification
or enzymatic interventions – two widespread methods
currently used to perform such analyses.
"Nanosphere's new SNP
analysis methodology for whole genomic human DNA is
a powerful example of the versatility of our proprietary
ClearReadTM nanoparticle technology," said William
Moffitt, Nanosphere's President and CEO. "This
study and the use of nanoparticles to dramatically
increase sensitivity in our other proprietary applications
-- such as bio-barcode for ultra sensitive detection
of proteins -- demonstrate the broad applicability
of nanotechnology and its potential to markedly advance
the state-of-the-art in nucleic acid and proteomic
research and diagnostics."
The analysis of whole human
genomic DNA is extraordinarily complex as it requires
sifting through the more than one billion base pairs
of DNA to find a particular base pair of interest.
Once that base pair is located, it is then necessary
to determine if either of the bases is mutated (i.e.,
has SNPs). Nanosphere's technology can rapidly, easily,
and accurately interrogate both bases in the pair
to determine if they are homozygous (i.e., both are
mutant or normal) or heterozygous (i.e., one is mutant,
one is normal) – the most critical step in correlating
the SNP with a disease or drug sensitivity.
To do so, Nanosphere scientists
employ a two-step process called ClearReadTM technology.
This method sandwiches a target DNA SNP segment between
two oligonucleotide sequences to greatly increase
detection specificity and sensitivity. One segment
identifies any mutations in the DNA and the probe,
a highly sensitive gold nanoparticle, creates a strong
signal accurately indicating the presence of a specific
target SNP. Proof of principle, reproducibility, and
the robust, simple and rapid characteristics of this
technology were demonstrated with unamplified DNA
samples representing all possible forms of three genes
implicated in hypercoagulation disorders.
Nanosphere (www.nanosphere-inc.com) is a nanotechnology-based
life sciences company in Northbrook, Illinois that
is using the application of proprietary nanotechnology
to create new standards in medical care and public
safety. With a universal VerigeneTM product platform
for the detection of nucleic acids and proteins, Nanosphere
is rapidly advancing the development of assays for
genomic and proteomic research, clinical laboratories
and point-of-care markets.