Extracellular matrix The extracellular matrix (ECM) is the part of the tissue that is situated outside of animal cells within the intercellular space. Fibroblasts that are situated in connective tissue express collagen, which, in combination with proteoglycans, is crucial for the stability of the ECM. The biological functions of the ECM are multifaceted and include the shaping of tissues and organs, stabilization of bones, elasticity and tensile strength of tissues, support of signal transduction, and the storage and supply of water, nutrition and hormones. The extracellular matrix consists of fibers and a basic compound. The basic compound is heterogenic and is composed of glycosaminoglycanes (GAG),proteoglycans and different adhesion proteins, as for example laminin, vitronectin or fibronectin. In histological sections, the space these substances occupy between fibers appears empty. The fibrous component is dominated by the collagen family of proteins, which form various types of fibers and are part of almost every tissue. The GAGs, which are carbohydrates, associate with proteins and form large complexes of macromolecules that belong to the proteoglycan family. The multitude of possible interactions of these proteins and molecules is the basis for the large spectrum of functions the extracellular matrix exhibits. Hint: On antibodies-online.com you find more than 8,200 antibodies specific for proteins of the extracellular matrix.