Progranulin is a 67-88 kDa glycoprotein, also known as acrogranin, PC-cell-derived growth factor, granulin-epithelin precursor, and proepithelin. This protein is present in a variety of mouse, rat, and human tissues. Progranulin, which is a growth factor, mediates cell cycle progression and cell migration in normal and pathological conditions. In several types of cancers, progranulin expression is upregulated, whereas function-interfering mutations in the granulin gene in humans have been linked to a subset of heritable cases of frontotemporal lobar degeneration. Also, progranulin has important effects on mouse preimplantation embryo development in vitro, including regulation of the appearance of the epithelium in the developing mouse blastocyst and growth of trophectoderm. Furthermore, progranulin promotes mouse blastocyst hatching, adhesion, and outgrowth in vitro. In this chapter, we describe some of the techniques that may be useful in the study of progranulin in embryo development.