Calculating microspheres per gram

During scientific experiment design and analysis it is common to need to know the number of spheres per gram of dry material.  We have put together the table below to help speed up the process.

If you have material of a density different from those listed in the table, divide the number of spheres per gram in the density ~1.0 g/cc column by the true particle density of your material to get an estimate of the number of spheres per gram.

Note: This table assumes the mean diameter is half way between the upper and lower size.

Monodisperse Silica Microspheres

Scientists are always pushing the limits, and looking for more precise products and equipment to enable the next technology.   In an effort to provide those scientists with the right tools Cospheric LLC has added monodisperse silica microspheres to their broad product line.

Silica particles are now available in distributions of less than 10% CV in the sizes of 1.0 micron, 4 micron and 8 micron.

Silica Microsphere Products now available:

SIO2MS 1.0um  <10% CV

SIO2MS 4.0um <10% CV

SIO2MS 8.0um <10% CV

SIO2MS 4-6um  (2-19um range)

High Density Glass Microspheres

Barium Titanate Glass microspheres are high density solid glass spheres.  At a Density of 4.5g/cc these solid glass spheres can be used for many scientific applications where high density and optical clarity is needed.  In addition to high density they also offer an index of refraction of more than 1.9.

Bulk quantities are available in 30-100um and 0.3-1.0mm size ranges.

For experiments requiring the highest precision the beads can be purchased in classified grades offering >90% of the spheres within a specific size range.  Standard Sizes include the narrow ranges below.

38-45um, 45-53um, 53-63um, 63-75um, 75-90um, 90-106um, 0.25mm-0.3mm, 0.3mm-0.35mm, 0.36mm-0.42mm, 0.43mm-0.5mm, 0.5mm-0.6mm, 0.6mm-0.7mm, 0.71mm to 0.85mm, and 0.85mm to 1.0mm.

Product pricing and availability can be found under Cospheric’s BTGMS (barium titanate glass microspheres)

Magnetic Microspheres – New Size Ranges Offered

106-125um magnetic Microspheres

Cospheric announces new particle size ranges for its BKPMS, Paramagnetic Microsphere product.

Thanks to customer demand for narrower particle size ranges of paramagnetic microspheres.  These highly opaque microspheres are homogeneous PE and often used in microscopy for high contrast cross sections.

Cospheric has added the following sizes to its extensive inventory of microspheres offered in the dry powder form:

• 10-20 micron, 0.1 grams
• 20-27 micron, 0.5 grams
• 27-32 micron, 1.0 grams
• 32-38 micron, 5.0 grams
• 38-45 micron, 5.0 grams

These sizes are in addition to its extensive range of black magnetic microspheres available up to 1.0mm (1000 micron) in diameter.

Density Marker Beads – Microspheres with Specific gravity of 1.065 and 1.075

Product Announcement:

Red 1.065 g/cc Spheres

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.  Two microsphere products having densities of 1.065 g/cc and 1.075 g/cc were recently released.

Blue 1.075g/cc Spheres

These spheres are offered with density tolerances of ±0.005 g/cc enabling excellent stratification, and bright blue and red coloration for high visibility with the unaided eye.

R&D Quantities are in stock and ready to purchase in sizes from 10um to 600um, larger 1kg+ quantities can be made to order to existing specifications or made to your custom color and density requirements. For more information visit:  Blue Density Marker Beads 1.075g/cc,  Red Density Marker Beads 1.065g/cc

Some Materials which have densities close to these markers are¹:

Source:
1 – Courtesy of Amersham Biosciences