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Displaying 1 - 15 of 15

Live quantification of cell viability via neutral red uptake using lens-free imaging

October 27, 2019
Author(s)
Brian J. Nablo, Jungjoon Ahn, Kiran Bhadriraju, Jong M. Lee, Darwin Reyes-Hernandez
We present the quantification of cell viability during neutral red (NR) uptake with a compact lens-free system utilizing two light sources. Conventionally, the NR uptake assay determines cell viability based on the accumulation of NR within lysosomes and

FINE-TUNING ELECTRICAL FLOW RATE SENSING IN DEFORMABLE CHANNELS

October 9, 2016
Author(s)
Pengfei Niu, Brian J. Nablo, Kiran Bhadriraju, Darwin Reyes-Hernandez
Here we present conclusive proof that when using electrical impedance to measure volumetric flow rate in polydimethylsiloxane (PDMS) microchannels a considerable fraction of the change in impedance, due to change in flow rate, is caused by the variation in

Dimensional Reduction of Duplex DNA Under Nanofluidic Slit Confinement

August 19, 2015
Author(s)
Luis Fernando Vargas Lara, Jack F. Douglas, Samuel M. Stavis, Elizabeth A. Strychalski, Jon C. Geist, Brian J. Nablo
There has been much recent interest in the dimensional properties of duplex DNA under nanoscale confinement conditions as a problem of fundamental interest in both technological and biological fields. This has led to a series of measurements by

The MEMS 5-in-1 Test Chips (Reference Materials 8096 and 8097)

March 27, 2013
Author(s)
Janet M. Cassard, Jon C. Geist, Craig D. McGray, Richard A. Allen, Muhammad Y. Afridi, Brian J. Nablo, Michael Gaitan, David G. Seiler
This paper presents an overview of the Microelectromechanical Systems (MEMS) 5-in-1 Reference Material (RM), which is a single test chip with test structures from which material and dimensional properties are obtained using five documentary standard test

Trapping and Release of Citrate-Capped Gold Nanoparticles

August 1, 2011
Author(s)
Darwin R. Reyes-Hernandez, Geraldine I. Mijares, Brian J. Nablo, Kimberly A. Briggman, Michael Gaitan
An electrical method to trap and release charged gold nanoparticles on and from the surface of alkanethiol self-assembled-monolayer (SAM) modified gold electrodes is presented. Gold nanoparticle (GNP) coated electrodes were formed by immersing amine

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

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