Density marker beads offer enable excellent stratification, and bright coloration for high
visibility with the unaided eye.
Density marker beads of accurately known mass density are generally used
as an external marker to facilitate the monitoring of the density
gradient shape and range. Historically density calibration beads in the size ranges of
212-250um or 250-300um are used. The
density marker beads provide a rapid, simple, and accurate method for
measuring the density. Generally a set of several such beads, covering a
range of densities, is used. In the biomedical industry researchers are
sometimes looking for cells having targeted specific gravities. In
order to locate these cells in test tubes it is useful to have colored
marker beads which will show where the delineation between specific
densities occurs. Density marker beads are also used for calibrating
particles in other industries, such as agriculture, microbiology and
others.Contact us for a quote and lead time for your custom density microspheres application.
Density Marker Beads for Creation and Analysis of Density Gradients - In stock. Density marker beads are small colored microspheres of known mass density that are used
for calibrating density gradients and determining density in gradient columns. Density
gradients are often used for separations and purifucations of cells, viruses
and subcellular particles. Generally a set of several density marker
beads covering a range of densities is used.The gradient is
calibrated with beads that float at different heights within the column.
When a test sample is added to the column it drops until the point of
neutral buoyancy and the density is determined from the calibration
chart. Density gradient columns can be used to measure the density of
any sample.Cospheric Density Marker Beads are provided at a 20%
concentration in an aqueous solution in 2.5ml vials. Unlike density
which used to be manufactured by GE Healthcare and have been
discontinued, the Cospheric's colored microspheres are
ready for use right out of the vial, don't need to be swollen, will work
with any media, and do not change density over time.Resources on Creating Density Gradients: Biotechnology: Theory and Techniques, Volume I (Jones and Bartlett Series in Biology) by Jack Chirikjian and Chirikjian
(Jan 1, 1995) Pages 45-50 on Density Gradient Centrifugation.