In this chapter, we describe the preparation and use of b-PG, a biotinylated complex that specifically binds hyaluronan (1 ,2 ). The b-PG is derived from cartilage and consists of a trypsin fragment of the proteoglycan core protein and one of the link proteins. Because of its ability to bind to hyaluronan with high affinity and specificity, the b-PG agent has proved to be useful in the histochemical localization of hyaluronan and its quantitative analysis by an enzyme linked assay (1 ,2 ).
