Stainless steel beads have a density of 7.9g/cc. They are used mostly for grinding leaves and seeds. They are made of Type 316 stainless steel - the most corrosion resistant available.

See Separate Listings to order each Catalog #.
Cat. No. LS-79115ss        1.5mm dia       45g
Cat. No. LS-79123ss        2.3mm dia       90g
Cat. No. LS-79132ss        3.2mm dia       90g
Cat. No. LS-79635ss        6.35mm dia     100 beads

*Note: These beads are not sold in one pound amounts.

Stainless steel beads can be cleaned and reused.

A more economic and time-saving option is to use ChromeSteel beads. These beads are much less expensive than stainless beads. Consequently, they can be used once and discarded.

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Information For Cell Disruption Applications

Size of Beads

When working with Bacteria use the 0.1mm diameter glass beads.
When working with Yeast/Fungi use the 0.5mm diameter glass beads.
When working with Most Tissue use the 1.0mm diameter glass beads or zirconia/silica beads.
When working with Skin or 'soft' plant material use a 2.0mm diameter zirconia beads.
When working with tough or fibrous tissue use the same sized beads (see above) but choose a more dense bead material. For example, researchers prefer 0.1mm zirconia-silica beads for disruption of spores or 2.3 mm chrome-steel beads for extraction of tough fibrous plant material like monocotyledon leaves. Some users have had good results using the MiniBeadbeater in a 'dry grinding' process - either at ambient or at liquid nitrogen temperatures. For example, a single seed can be pulverized into a fine powder in 30 seconds using one 6.3 mm diameter chrome steel bead in our 2 or 7 ml vials.
Critique: Special and supposedly unique combinations of different sizes and types of beads in the same vial are mostly marketing hype from certain vendors of pre-filled microvials. There is little, if any, comparative documentation available to back up their claims of enhanced performance. With limited exception, measurable improvements in cell lysis derived from "magic" bead combinations are marginal.

Density of Beads

Glass has a density of 2.5 g/cc (most commonly used bead media for 'Beadbeating')
Zirconia/Silica has a density of 3.7g/cc (50% more dense than glass - good for spores and most tissues)
Silicon Carbide (sharp particle, not a bead) has a density of 3.2 g/cc (May work faster on tough tissue samples because the particles have sharp cutting edges. Their utility is still under investigation, but see Brein's comments below)
Garnet (an iron-aluminum silicate, sharp particle) has a density of 4.1 g/cc. Like SiC particles, it may accelerate lysis of tough tissue due to its sharp edges. However, garnet particles are easily fragmented during beadbeating. Facile separation of the final grinding media from the homogenate can be problematic. Nevertheless, this very fragementation during beadbeating may be useful when homogenizing tissue, fecal or soil samples containing bacteria because you end up with a useful size mix of grinding media that can both rapidly disperse the sample and also disrupt the microorganism. For this specialized application, start off with the vial containing 1 or 2 mm sized grinding particles.
Zirconia has a density of 5.5g/cc (100% more dense than glass - good for tough tissue). Chemically inert and resistant to fragmentation.
ChromeSteel and Stainless Steel has a density of 7.9g/cc . Used mostly for grinding leaves and seeds. Only 1-3 steel beads are added to the microvial. Stainless steel beads are expensive but reusable. Chrome steel beads are a recommended substitute for s.s. beads. They are 10X cheaper...cheap enough to be use once and thrown away. Thus, no cleaning or cross-contamination concerns.
Tungsten Carbide has a density of 14.9g/cc. While very dense, this bead is generally not used for biopreps - it leaves prep dirty.