Images were captured using the AX70 microscope via a video linkage to an Apple Macintosh (Cupertino, CA) computer utilizing the program NIH Image 1.60b7 or were photographed using the Vanox microscope with Olympus C35AD-4 camera attachment. Photographs used in all the illustrations here were taken using Kodak (Eastman Kodak, Rochester, NY) T-Max 400 black-and-white film. ampicillin antibiotic
Western Blotting of Type IV Collagen NC1 Domains
To release the NC1 domain of type IV collagen, the tissues were homogenized and then digested at 37°C for 24 h with collagenase (50 mg/ml, CLS1, 238 U/mg; Worthington Biochemical Corporation, Freehold, NJ) in Hepes-buffered (50 mM; pH 7.5) calcium chloride solution (10 mM) containing protease inhibitors (4 mM A-ethylmalemide, 1 mM PMSF, 5 mM benzamidine hydrochloride, 25 mM e-ami-nocaproic acid); 2 ml of collagenase solution was used per gram of tissue. The digestion was terminated by the addition of EDTA (to a final concentration of 25 mM). Samples were then centrifuged (10000 X g, 10 min), and the supernatants were stored at -20°C until required.