BPI Tech offers a wide selection of beads in terms of their chemical composition, size and density to enable customers to easily optimize their homogenization based on the nature of biological sample materials and type of instruments used. Our zirconia beads are inert, resist disintegration, and have higher density, that provide additional energy to improve breakage/homogenization of tough cells and tissues.
Bead Density Information
We have a wide selection of beads with in a wide range of sizes from 45µm to all the way up to 6.35 mm in diameter.
The beads we employ are higher in density (6.2 cc/g for Endure beads and 7.9 g/cc for steel beads) with inert surface chemistry.
Ideal for nucleic acid and protein isolation; effective against bacteria, spores, yeast, fungi, plant and animal tissues.
The beads are also available sterile and are packed in 50 g and 100 g quantities.
Beads come dispensed in 0.5 ml, 2 ml, 10 ml, and 15 ml tubes for easy sample processing.
Our 3″ GrindSticks are sterile and come individually packed; ideal for effective hand homogenization.
Bead Beating – Some Consderations
DNA shearing – Excessive force will rupture cells and at the same time will result in DNA shearing and thus will reduce the quality of isolated DNA. Though DNA shearing may not be a factor in PCR amplification, it will affect the shelf life and be a limitation in certain downstream applications that require relatively larger DNA fragments.
High temperature and excessive shearing will denature proteins and increase the wear of grinding materials.
Successful temperature control includes pre-chilling of samples and containers, runs of short duration with rest time to allow for re-chilling samples on ice and fewer beads and/or extra buffer to act as heat sink, and reduced degree of shaking vigor.
Chemical contamination of grinding media is usually rare. To mitigate this problem, chose beads that are inert, such as zirconium oxide stabilized with yittria. Glass beads are basically silica and lower in density. Due to wear, bead surfaces could become reactive in the presence of salt solutions that are commonly used in homogenization. Garnet beads are generally inert but have poor wear resistance. These beads could break up, generating dust and thus chemically contaminating samples.
Bead size – Bacteria requires beads of 0.1 to 0.5 mm in diameter, while yeast, algae and fungal hyphae use beads of 0.5 to 1.2 mm in diameter. For homogenization of plant and mammalian tissues, chop the tissues and use beads of 1 to 5 mm in diameter. You can freeze the tissues before homogenization.