A novel assay to evaluate promoting effects of proteins on calcium oxalate crystal invasion through extracellular matrix based on plasminogen/plasmin activity

► We have successfully developed, for the first time, a crystal invasion assay. ► This novel crystal invasion assay is based on the plasminogen/plasmin activity. ► This novel assay can be applied to evaluate effects of proteins on crystal invasion. ► Albumin markedly induced crystal invasion, whereas other proteins had no effects.