Open Access. Powered by Scholars. Published by Universities.®

Biochemical and Biomolecular Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Articles 31 - 43 of 43

Full-Text Articles in Biochemical and Biomolecular Engineering

Laboratory Automation Education, James D. Sterling Jan 2004

Laboratory Automation Education, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

No abstract provided.


Resolution Of Multiple Ssdna Structures In Free Solution Electrophoresis, Eve F. Fabrizio, Ali Nadim, James D. Sterling Oct 2003

Resolution Of Multiple Ssdna Structures In Free Solution Electrophoresis, Eve F. Fabrizio, Ali Nadim, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

By using high concentrations of buffer, electroosmotic flow within uncoated channels of a microfluidic chip was minimized, allowing the free solution electrophoretic separation of DNA. More importantly, because of the ability to efficiently dissipate heat within these channels, field strengths as high as 600 V/cm could be applied with minimal Joule heating (< 2 °C). As a result of the higher field strengths, separations within an 8-cm-long channel were achieved within a few minutes. However, when the electrophoretic separation of single-stranded DNA (ssDNA) less than 22 bases in length was performed, containing the fluorophore Texas Red as an end label, more than the expected single peak was observed at this high electric field. On the other hand, the free solution electrophoresis of a double-stranded DNA (dsDNA) consisting of a random sequence did exhibit the expected single peak. The appearance of these multiple peaks for ssDNA is shown to be dependent upon the base content and sequence of the ssDNA as well as on the chemical structure of the fluorophore used to tag the DNA for detection. Specifically, the peaks can be attributed to different secondary structures that result either from hydrophobic interactions between the DNA bases and an uncharged fluorescent dye or from G-quadruplexes within guanine-rich strands.


Sequence Dependent Mobility Of Short Oligonucleotides In Free-Solution Electrophoresis, James D. Sterling, Eve F. Fabrizio, Ali Nadim Jan 2003

Sequence Dependent Mobility Of Short Oligonucleotides In Free-Solution Electrophoresis, James D. Sterling, Eve F. Fabrizio, Ali Nadim

Business and Information Technology Faculty Research & Creative Works

No abstract provided.


Method, Apparatus And Article For Microfluidic Control Via Electrowetting, For Chemical, Biochemical And Biological Assays And The Like, James D. Sterling Nov 2002

Method, Apparatus And Article For Microfluidic Control Via Electrowetting, For Chemical, Biochemical And Biological Assays And The Like, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

An active-matrix microfluidic platform employs thin film transistor active ("TFT") matrix liquid crystal display ~ technology to manipulate small samples of fluid for chemical, biochemical, or biological assays without moving parts, for example, using a two-dimensional matrix array of drive electrodes. The active-matrix microfluidic platform may employ existing active matrix 0 addressing schemes and/or commercial "off-the-shelf" animation software to program assay protocols. A feedback subsystem may > determine an actual location of a fluid in the microfluidic structure, and provides location information to for display, for example, on an active-matrix display, and/or to control movement of one or more fluid bodies …


Studies On The Formation Of Dna-Cationic Lipid Composite Films And Dna Hybridization In The Composites, Murali Sastry, Vidya Ramakrishnan, Mrunalini Pattarkine, Krishna N. Ganesh May 2001

Studies On The Formation Of Dna-Cationic Lipid Composite Films And Dna Hybridization In The Composites, Murali Sastry, Vidya Ramakrishnan, Mrunalini Pattarkine, Krishna N. Ganesh

Faculty Works

The formation of composite films of double-stranded DNA and cationic lipid molecules (octadecylamine, ODA) and the hybridization of complementary single-stranded DNA molecules in such composite films are demonstrated. The immobilization of DNA is accomplished by simple immersion of a thermally evaporated ODA film in the DNA solution at close to physiological pH. The entrapment of the DNA molecules in the cationic lipid film is dominated by attractive electrostatic interaction between the negatively charged phosphate backbone of the DNA molecules and the protonated amine molecules in the thermally evaporated film and has been quantified using quartz crystal microgravimetry (QCM). Fluorescence studies …


Cationic Surfactant Mediated Hybridization And Hydrophobization Of Dna Molecules At The Liquid/Liquid Interface And Their Phase Transfer, Murali Sastry, Ashavani Kumar, Mrunalini Pattarkine, Vidya Ramakrishnan, Krishna N. Ganesh Jan 2001

Cationic Surfactant Mediated Hybridization And Hydrophobization Of Dna Molecules At The Liquid/Liquid Interface And Their Phase Transfer, Murali Sastry, Ashavani Kumar, Mrunalini Pattarkine, Vidya Ramakrishnan, Krishna N. Ganesh

Faculty Works

Hybridization of complementary oligonucleotides mediated by a cationic surfactant at the water/hexane interface leads to hydrophobic, double-helical DNA which may be readily phase transferred to the organic phase and cast into thin films on solid substrates.


Hybridization Of Dna By Sequential Immobilization Of Oligonucleotides At The Air-Water Interface, Murali Sastry, Vidya Ramakrishnan, Mrunalini Pattarkine, Anand Gole, K. N. Ganesh Nov 2000

Hybridization Of Dna By Sequential Immobilization Of Oligonucleotides At The Air-Water Interface, Murali Sastry, Vidya Ramakrishnan, Mrunalini Pattarkine, Anand Gole, K. N. Ganesh

Faculty Works

The hybridization of DNA by sequential electrostatic and hydrogen-bonding immobilization of single-stranded complementary oligonucleotides at the air-water interface with cationic Langmuir monolayers is demonstrated. The complexation of the single-stranded DNA molecules with octadecylamine (ODA) Langmuir monolayers was followed in time by monitoring the pressure-area isotherms. A large (and slow) expansion of the ODA monolayer was observed during each stage of complexation in the following sequence: primary single-stranded DNA followed by complementary single-stranded DNA followed by the intercalator, ethidium bromide. Langmuir-Blodgett (LB) films of the ODA-DNA complex were formed on different substrates and characterized using quartz-crystal microgravimetry (QCM), Fourier transform infrared …


Anion Induced Blue To Purple Transition In Bacteriorhodopsin, Mrunalini Pattarkine, Anil K. Singh Jun 1996

Anion Induced Blue To Purple Transition In Bacteriorhodopsin, Mrunalini Pattarkine, Anil K. Singh

Faculty Works

Purple membrane (PM, λ" role="presentation">λmax" role="presentation">max 570 nm) of H. halobium on treatment with sulphuric acid changes its colour to blue (λ" role="presentation">λmax" role="presentation">max 608 nm). The purple chromophore can be regenerated from the blue chromophore by exogeneous addition of anions such as CI−" role="presentation">− and HPO42−" role="presentation">2−4. Chloride ion is found to be more effective than the dibasic phosphate ion in regenerating the purple chromophore. Nevertheless, one thing common to the anion regeneration is that both CI−" role="presentation">− and HPO42−" role="presentation">2−4 show marked pH effect. At pH 1.0 the efficiency of …


A Lattice Boltzmann Subgrid Model For High Reynolds Number Flows, S. Hou, James D. Sterling, S. Chen, G. D. Doolen Jan 1996

A Lattice Boltzmann Subgrid Model For High Reynolds Number Flows, S. Hou, James D. Sterling, S. Chen, G. D. Doolen

Business and Information Technology Faculty Research & Creative Works

A sub grid turbulence model for the lattice Boltzmann method is proposed for high Reynolds number fluid flow applications. The method, based on the standard Smagorinsky sub grid model and a single-time relaxation lattice Boltzmann method, incorporates the advantages of the lattice Boltzmann method for handling arbitrary boundaries and is easily implemented on parallel machines. The method is applied to a two-dimensional driven cavity flow for studying dynamics and the Reynolds number dependence of the flow structures. The substitution of other sub grid models, such as the dynamic sub grid model, in the framework of the LB method is discussed.


Gas Dynamic Unstart In Superdetonative Ram Accelerators, Kaveh Ghorbanian, James D. Sterling Jan 1996

Gas Dynamic Unstart In Superdetonative Ram Accelerators, Kaveh Ghorbanian, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

In this paper we analyze the reflection of non-reacting shock waves as oblique detonation waves. The 2D, steady, inviscid analysis makes use of detonation polar diagrams to identify incident shock angles that lead to reflected detonations, with and without detonation Mach stem formation. The implications of the results for design and operation of superdetonative ram accelerators are explored. The influence of the projectile forebody geometry, the propellant composition, and the takeover velocity is described. We conclude with a discussion of the significance of these parameters on superdetonative ram accelerator unstart phenomena.


Enhanced Combustion Pulsejet Engines For Mach 0 To 3 Applications, J. Sterling, K. Ghorbanian, T. Sobota Jan 1996

Enhanced Combustion Pulsejet Engines For Mach 0 To 3 Applications, J. Sterling, K. Ghorbanian, T. Sobota

Business and Information Technology Faculty Research & Creative Works

In this paper, we discuss the cyclic operation of an enhanced combustion pulsejet engine (ECPE) applicable in the Mach number range of 0 to 3. The geometry of this engine naturally provides for integration into a new combined cycle engine with ramjets. As in the operation of conventional pulsejets, an ECPE provides engine aspiration, charge compression, combustion and expansion without the use of turbomachinery. The use of modern electronics, fuel injection, and feedback control offers the potential for performance improvements that could make the ECPE a cost-effective competitor for the turbojet engine. This article describes the operating cycle of a …


Influence Of Formation Processes On Oblique Detonation Wave Stabilization, K. Ghorbanian, J. D. Sterling Jan 1996

Influence Of Formation Processes On Oblique Detonation Wave Stabilization, K. Ghorbanian, J. D. Sterling

Business and Information Technology Faculty Research & Creative Works

In this article we report steady, two-dimensional, inviscid solutions for the near field and far field of a supersonic reactive flow over a variable-double-ramp geometry. The incident shock wave compresses and heats the reactants that will combust after flowing some induction length. Upon reaction, a detonation wave forms and intersects the leading wave at some distance from the ramp surface. In this article, reaction-polar diagrams are developed, and the detonation branch solutions are used to investigate the wave interaction processes that may lead to a steady three-wave structure. By considering this formation process new oblique detonation wave stabilization criteria based …


Lattice Boltzmann Thermohydrodynamics, F. J. Alexander, S. Chen, J. D. Sterling Jan 1993

Lattice Boltzmann Thermohydrodynamics, F. J. Alexander, S. Chen, J. D. Sterling

Business and Information Technology Faculty Research & Creative Works

We introduce a lattice Boltzmann computational scheme capable of modeling thermohydrodynamic flows of monatomic gases. The parallel nature of this approach provides a numerically efficient alternative to traditional methods of computational fluid dynamics. The scheme uses a small number of discrete velocity states and a linear, single-time relaxation collision operator. Numerical simulations in two dimensions agree well with exact solutions for adiabatic sound propagation and Couette flow with heat transfer. © 1993 The American Physical Society.