Search PubMed⌕ Search

PubMed · 8137785

Electrophoretic light scattering.

Abstract

Under a microscope, electrophoretic mobilities of visible particles can be determined in a free solution without any boundary or zonal separation. Electrophoretic light scattering based on the Doppler velocimetry can be taken as a nanometer-scale version of the above traditional electrophoresis. An electrophoretic light scattering apparatus was developed to enable mobility determination of proteins and surfactant micelles which have been outside the range of the electrophoresis.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

T Takagi. 1993. Electrophoretic light scattering.. https://doi.org/10.1002/elps.11501401190

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

A model for melanosome biogenesis based on the purification and analysis of early melanosomes.

Melanosome biogenesis and function were studied after purification of early stage melanosomes and characterization of specific proteins sorted to that organelle. Melanosomes were isolated from highly pigmented human MNT1 melanoma cells after disruption and initial separation by sucrose density gradient centrifugation. Low-density sucrose fractions were found by electron microscopy to be enriched in stage I and stage II melanosomes, and these fractions were further separated and purified by free flow electrophoresis. Tyrosinase and dopachrome tautomerase (DCT) activities were found exclusively in stage II melanosomes, even though DCT (and to some extent tyrosinase) proteins were sorted to stage I melanosomes. Western immunoblotting revealed that these catalytic proteins, as well as TYRP1, MART1, and GP100, were cleaved and inactivated in stage I melanosomes. Proteolytic cleavage was critical for the refolding of GP100 within the melanosomal milieu, and subsequent reorganization of amorphous stage I melanosomes into fibrillar, ovoid, and highly organized stage II melanosomes appears to stabilize the catalytic functions of melanosomal enzymes and allows melanin biosynthesis to begin. These results provide a better understanding of the structural features seen during melanosome biogenesis, and they yield further clues as to the physiological regulation of pigmentation.

Electrophoresis↗

Discrete spacers for photometric characterization of humic acids separated by capillary isotachophoresis.

A group of twenty discrete spacers suitable for photometric characterization of humic acids (HAs) after their isotachophoretic (ITP) separation at pH 10 was found. The spacers, inorganic and organic acids and amino acids of suitable acid-base and migration properties exhibiting no light absorption in the UV region of the light spectrum, made possible to perform this characterization in a sensitive spike mode of the ITP analysis. Using this approach a complex mixture of humic constituents present in a test HA preparation was separated into 22 fractions migrating in the interzonal boundary layers formed by the zones of discrete spacers and 21 fractions mixed with the zones of the spacers. A photometric monitoring of the fractions in the ITP stack at a 405 nm detection wavelength provided an adequate selectivity and sensitivity into the characterization. Relative sizes of the detected fractions of the test HA preparation ranged from 0.2-0.3 to 27.5% (based on the response of the phototometric detector at 405 nm). The fractions representing ca. 0.2-0.3% of the total peak area could be still quantified when 800 ng of the test preparation was loaded onto the ITP column. A typical repeatability of the total area of the detection signal corresponding to humic constituents in the ITP stack was ca. 2.5%. Repeatabilities of the peak areas of the fractions of the humic constituents defined by the spacers ranged from 2 to 6% for the fractions representing 1% or more of the total area and from 8 to 12% for those representing less than 1%. No marks of aggregations of the humic constituents were detected and reproducible ITP profiles (fingerprints) of the studied humic preparation were achieved under the developed working conditions.

Electrophoresis↗