Extracel-X hydrogel hyaluronan-based synthetic extracellular matrix for preparing tumor xenografts in mice is lactate dehydrogenase-elevating virus (LDEV) free. To reconstitute the hydrogel, simply dissolve the contents of three of the vials, mix together, add cells, and inject. No low temperature handling needed. Kits are available in either three 2.5 ml (shown) or a single 12.5 ml aliquots.