Product Description: PODS® Empty crystals are composed solely of polyhedrin protein which self-assembles into regular, cubic crystals. Thus, these PODS® co-crystals do not contain any cargo protein, in contrast to other PODS® growth factor products, and are intended to be used as negative controls alongside cargo-containing PODS® co-crystals. The cross-reactivity of PODS® Empty crystals has been tested on a variety of cells including mouse ES cells, PC12, fibroblasts, and ETS embryos, and there was no observable interference with the tested cells. Additionally, in-vivo data indicate no inflammatory response to PODS® Empty crystals in animals.