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Displaying 26 - 50 of 83

PEG-Labeled Nucleotides and Nanopore Detection for Single Molecule DNA Sequencing by Synthesis

September 21, 2012
Author(s)
Shiv Kumar, Tao Chuanjuan, Chien Minchen, Hellner Brittney, Joseph W. Robertson, Arvind Balijepalli, Li Zengmin, James J. Russo, Joseph E. Reiner, John J. Kasianowicz, Jingyue Ju
There is a significant need to accurately sequence single DNA and RNA molecules for personalized medicine. We describe a novel nanopore-based sequencing by synthesis (SBS) strategy that will accurately differentiate at single molecule level four different

SEM Induced Shrinking of Solid State Nanopores for Single Molecule Detection

September 22, 2011
Author(s)
Anmiv Prahbu, Kevin J. Freedman, Joseph W. Robertson, Zhorro Nikolov, John J. Kasianowicz, MinJun Kim
We have investigated the shrinkage of solid state nanopores by a scanning electron microscope and find the process to be reproducible and dependant beam parameters such as the accelerating voltage and electron flux. The shrinking phenomenon does not

Theory for Polymer Analysis Using Nanopore-based Single-molecule Mass Spectrometry

June 1, 2010
Author(s)
Joseph E. Reiner, John J. Kasianowicz, Brian J. Nablo, Joseph W. Robertson
Nanometer-scale pores have demonstrated potential as a tool for the electrical detection and characterization of molecules. To provide a physical basis for nanopore-based analytical metrology, we show that a simple model quantitatively describes how one

Probing Single Nanometer-Scale Pores with Polymeric Molecular Rulers

April 2, 2010
Author(s)
Sarah E. Henrickson, Edmund A. DiMarzio, Qian Wang, Vincent M. Stanford, John J. Kasianowicz
It has been shown that individual molecules of single stranded DNA can be driven electrophoretically through a single Staphylococcus aureus ?-hemolysin ion channel. Polynucleotides thread through the channel as extended chains and the polymer-induced ionic

Model for the Asymmetric DC and Fluctuating Conduction of an Ion Channel

October 16, 2008
Author(s)
B Robertson, John J. Kasianowicz
A model for the asymmetric DC conduction of an ion channel is compared with measurements of the ionic current carried by an aqueous potassium chloride solution through ion channels formed by alpha hemolysin in a lipid bilayer. The dependence of the current

Sizing the Bacillus anthracis PA63 Channel with Nonelectrolyte Poly(ethylene glycols)

August 1, 2008
Author(s)
Brian J. Nablo, Kelly Halverson, Joseph W. Robertson, Tam Nguyen, Rekha Panchal, Rick Gussio, Sina Bavari, Oleg V. Krasilnikov, John J. Kasianowicz
Non-electrolyte polymers of poly(ethylene glycol), PEG, were used to estimate the diameter of the ion channel formed by Bacillus anthracis protective antigen 63, PA63. Based on the ability of different molecular weight PEGs to partition into the pore and

Nanoscopic Porous Sensors

July 1, 2008
Author(s)
John J. Kasianowicz, Joseph W. Robertson, Elaine Chan, Joseph E. Reiner, Vincent M. Stanford
There are thousands of different nanometer-scale pores in biology,many of which act as sensors for specific chemical agents. Recent work suggests that protein and solid-state nanopores have many potential uses in a wide variety of analytical applications

The Detection and Characterization of Ions, DNA and Proteins with Nanometer-Scale Pores

December 1, 2007
Author(s)
John J. Kasianowicz, Jeffrey C. Lerman, Sarah E. Henrickson, Martin Misakian, Rekha Panchal, Kelly Halverson, Sina Bavari, Tam Nguyen, Rick Gussio, Devanand K. Shenoy, Vincent M. Stanford
Protein ion channels are nanometer-scale pores that are central to many biological processes, including the sensing of a wide variety of molecules. They have also demonstrated their potential for use in the sensitive and selective detection of ions, the

Liposome Characterization with Fluorescence Cumulant Analysis

June 8, 2007
Author(s)
Joseph E. Reiner, Andreas Jahn, Laurie E. Locascio, Michael Gaitan, John J. Kasianowicz
Liposomes are self-assembled spherical vesicles comprised of a lipid bilayer membrane that segregates an internal aqueous environment from an external aqueous environment. These nanometer-scale structures have demonstrated potential for targeted drug

Numerical Fluorescence Correlation Spectroscopy for Molecular Dynamics Analyses Under Non-Standard Conditions

June 1, 2007
Author(s)
Michael J. Culbertson, Joshua T. Williams, Wayland Cheng, Dee A. Stults, Emily R. Wiebrach, John J. Kasianowicz, Daniel L. Burden
A major concern in Fluorescence Correlation Spectroscopy (FCS) pertains to the accuracy of standard mathematical models that are used to extract kinetic information from correlated data. The standard equations used in FCS arise from a simple Gaussian model

Single Molecule Mass Spectrometry in Solution Using a Solitary Nanopore

May 15, 2007
Author(s)
Joseph W. Robertson, Claudio G. Rodrigues, Oleg V. Krasilnikov, Vincent M. Stanford, Kenneth A. Rubinson, John J. Kasianowicz
A solitary protein nanometer-scale pore provides the basis for single molecule mass spectrometry in solution. Individual poly(ethylene glycol) molecules of different mass that enter a nanopore cause distinct and statistically resolved conductance states