Lysing matrix Z contains 2.0 mm diameter yttrium-stabilized zirconium oxide beads. These beads have high density and extremely high hardness making this matrix ideal for cracking of very tough cell walls, while its smooth surface minimizes shearing. Lysing matrix Z is used primarily for lysis of animal and plant tissue, tougher stems, roots and seeds, and whole insects. Matrix Z is an alternative to the very aggressive matrix a because its lower shear rate minimizes degradation in applications such as RNA and protein isolation from very tough tissue.