Negative Panning Phase
Negative Panning Phase - Related Videos
02:39
Phase Diagrams
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2020
A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature and also provide the pressure dependence of the phase-transition temperatures (melting points, sublimation points, boiling points). Regions or areas labeled solid, liquid, and gas represent single phases, while lines or curves represent...
02:31
Phase Transitions
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2020
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to occupy...
09:51
Single Phase Inverter
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2023
Source: Ali Bazzi, Department of Electrical Engineering, University of Connecticut, Storrs, CT. DC power is unidirectional and flows in one direction, whereas, AC current alternates directions at a frequency of 50-60 Hz. Most common electronic devices are designed to run off of AC power; therefore an input DC source must be inverted to AC. Inverters convert DC voltage to AC through switching action that repeatedly flips the polarity of the input DC source at the output or load side for part of...
11:15
Single Phase Rectifiers
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2023
Source: Ali Bazzi, Department of Electrical Engineering, University of Connecticut, Storrs, CT. A DC power supply is generally considered to be a device that supplies DC, or unidirectional, voltage and current. Batteries are one such power supply, however, they are limited in terms of lifetime and expense. An alternative method to providing unidirectional power is to transform AC line power to DC power using a rectifier. A rectifier is a device that passes current in one direction, and blocks...
02:33
Phase Transitions: Sublimation and Deposition
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2020
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
FAQs
The step changes library composition by separating members according to whether they recognize an unwanted binding context. Library molecules that attach to the irrelevant surface, matrix, or control molecule are removed from the pool. Molecules that remain unbound are retained for subsequent target-directed enrichment, so later selection begins with fewer candidates likely to create background interactions.
An irrelevant surface, matrix, or control molecule provides the test environment for unwanted binding. It exposes library members to materials that should not be recognized in the intended application. Removing molecules that bind this control helps distinguish target-related recognition from attachment caused by surrounding materials, improving the specificity of the remaining candidate pool.
Negative panning and positive panning serve complementary purposes. Negative panning removes candidates that recognize irrelevant materials, whereas positive panning enriches candidates that bind the intended target. Using the steps together shifts selection from simple target attachment toward target recognition with reduced background binding and cross-reactivity, producing candidates with more useful binding profiles.
Cross-reactive candidates may bind materials other than the intended target, making their later use less specific. Negative panning addresses this problem by removing library members that attach to selected irrelevant materials before target-specific enrichment. The resulting pool is more likely to contain recognition molecules whose binding behavior is useful for bioengineering research and biotechnology applications.
The library is incubated with an irrelevant surface, matrix, or control molecule and then considered according to its binding behavior. Members that attach to the control material are discarded, while members that remain unbound continue to positive panning against the intended target. This fractionation converts negative binding information into a practical filter before enrichment.
This selection step supports projects that seek targeted antibodies, peptides, and other recognition molecules with more selective binding profiles. By lowering background binding before target enrichment, it can improve the starting quality of candidates for research and biotechnology applications. Its value is greatest when recognition of unintended materials or cross-reactivity would reduce the usefulness of the selected probes.