Beta actin is one of six different actin isoforms which have been identified. Actins are highly conserved proteins that are involved in cell motility, structure and integrity.Be aware when using beta actin antibodies as loading controls that although beta actin is normally the best protein to use as a loading control, under some conditions its amounts can vary between samples. In particular, expression of actin in adipose tissue is very low (Spiegelman and Farmer, Cell, 1982, 29(1):53-60) "in cells undergoing adipose differentiation actin synthesis decreases by 90%".