The major ampullate (MA) gland, which is named after its morphological features, represents the most extensively studied silk-producing gland in the spider silk com­munity (Fig. 1.1). From an anatomical perspective, it has been divided into three regions: the tail region, the ampulla and the spinning duct. The tail region is respon­sible for the synthesis of large quantities of silk protein, the ampulla for silk protein storage, and the spinning duct functions to facilitate the conversion of the liquid dope into a solid. Recent studies have pinpointed three different types of epithelial cells that span the tail and ampulla region; these regions are denoted zones A, B and C.2 The MA gland produces silk for the web frame and radii and serves as a lifeline for spiders to move and escape predators (Table 1.1). MA silk evolved long before its use in orb-webs, being used as far back as 350 mya.3 One primary function of dragline silk includes locomotion; however, it is becoming apparent that MA silk performs a variety of other tasks. In particular, biochemical studies have shown that cob-weavers use MA silk to form web scaffolding and gumfooted lines, two impor­tant fiber types that facilitate prey capture.4 In some instances, it has been reported to be present in prey wrapping silk.5 There are essentially three reasons that MA silk has been the most extensively studied: 1) The MA gland represents the largest and easiest structure to identify during microdissection of the different silk-producing glands; 2) MA silk represents the easiest silk type to forcibly remove or collect from a spider during a controlled descent; 3) MA silk has extraordinary mechanical prop­erties, which include its high tensile strength and toughness.