Alpha Fractions
Alpha Fractions - Related Videos
09:27
Sequential Extraction of Soluble and Insoluble Alpha-Synuclein from Parkinsonian Brains
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Cited by 46 •
2016
Here, we present a protocol for the isolation of increasingly insoluble/aggregated alpha-synuclein (α-syn) from post-mortem human brain tissue. Through the utilization of buffers with increasing detergent strength and high-speed ultracentrifugation techniques, the variable properties of α-syn aggregation in diseased and non-diseased tissue can be examined.
10:09
Fractional Distillation
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2023
Source: Laboratory of Dr. Nicholas Leadbeater — University of Connecticut Distillation is perhaps the most common laboratory technique employed by chemists for the purification of organic liquids. Compounds in a mixture with different boiling points separate into individual components when the mixture is carefully distilled. The two main types of distillation are "simple distillation" and "fractional distillation", and both are widely used in organic chemistry laboratories. Simple distillation...
01:30
Detection of Phosphorylated Alpha-Synuclein Using Western Blotting
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2025
Add a loading buffer containing a detergent, a reducing agent, and a tracking dye.
03:25
Immunostaining of Neurons Treated with Alpha-Synuclein Aggregates
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2025
This video demonstrates the immunostaining of neurons treated with alpha-synuclein (αS) aggregates. The neurons are first treated with αS aggregates. They are then fixed, permeabilized, and treated with a blocking solution. Primary antibodies are added, followed by a fluorescently labeled secondary antibodies and a nuclear stain. The sample is then mounted and observed under a microscope.
02:12
Induction of Neuroinflammation in Mice via Injection of Alpha-Synuclein Fibrils
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2025
This video demonstrates the injection of alpha-synuclein fibrils into a mouse to induce neuroinflammation. The fibrils are injected intraperitoneally into a transgenic mouse expressing mutated alpha-synuclein proteins. Upon reaching the central nervous system, the fibrils enter neurons and induce aggregation of the mutated proteins. The aggregates spread to neighboring neurons, microglia, and astrocytes. Recognition of the aggregates triggers microglia to induce neuroinflammation, damaging the...
FAQs
A change in pH shifts the equilibrium distribution among the available forms. More acidic conditions generally favor forms retaining more protons, whereas increasing pH favors successive deprotonation. The resulting alpha values therefore indicate not only which species is present, but also how sharply the composition changes across a selected pH range.
Each deprotonation step has its own dissociation constant, so proton loss occurs through a sequence of equilibria rather than a single event. The relative values of those constants determine where forms such as H₂A, HA⁻, and A²⁻ become important. This staged behavior helps connect calculated composition with regions of a titration curve.
Total analytical concentration reports how much substance is present overall, but it does not specify how that amount is divided among protonation states. Alpha fractions supply that distribution as proportions. Multiplying each proportion by the total concentration gives the amount associated with a particular form, allowing its likely chemical behavior to be considered separately.
The essential equilibrium inputs are the solution pH and the dissociation constants for the relevant proton-loss steps. The calculation also requires identifying the protonation states being considered, such as H₂A, HA⁻, and A²⁻. Once the fractions are obtained, the total analytical concentration can be used to estimate the amount of each form.
Alpha fractions show how the composition of an acid-base system changes with pH, helping chemists identify conditions where a desired protonation state is substantially represented. This information supports selection and adjustment of buffer systems, because the calculated distribution indicates how the chemical composition may respond within the pH range of interest.
Protonation state can influence how a substance behaves in solution, including its solubility, reactivity, and ability to complex metal ions. By calculating the distribution across forms at a selected pH, chemists can assess which species is likely to contribute most strongly to the observed behavior and evaluate how changing pH may alter that outcome.