Interactions between glycosaminoglycans (GAGs) and chemokines play a critical role in multiple physiological and pathological processes, including tumor metastasis and immune-cell trafficking. During our studies examining the genetic importance of the GAG subtype known as heparan sulfate (HS) on lymphatic endothelial cells (LECs), we established a repertoire of methods to assess how HS affects chemokine-mediated cell–cell interactions. In this chapter, we describe methods for monitoring migration and adhesion interactions of dendritic cells (DCs), the most potent antigen-presenting cells, with LECs. We will also report a methodology to assess chemokine–receptor interactions while incorporating approaches to target HS in the system. This includes in situ methods to visualize and quantify direct interactions between chemokines and chemokine receptors on DC surfaces, and how targeting HS produced by LECs or even DCs affects these interactions. These methods enable the mechanistic and functional characterization of GAG–chemokine interactions in cell-based studies that model physiologic interactions ex vivo. They may also be used to obtain novel insights into GAG-mediated biological processes.