... homogenate and medium byWestern-type dot-blot procedure. Spot aliquots of the homogenates or media on nitrocel-lulose paper, using the dot-blot apparatus and air-dry for 5 min. Perform all ensuing pro-cedures ... [35S]sulfate-labeled, TCA-precipitable proteins in tis-sue homogenate (j1) and medium (j2) (cpm/mL) (Note 10).k. Mature [35S]sulfate-labeled mucin band in tissue homogenate (k1) and medium (k2)on 4% SDS-PAGE ... equiv-alent apparatus) to quantify the amount of radioactivity in an identified band on SDS-PAGE.6. Poly- or monoclonal antibodies (IgG-type) against nonglycosylated regions of the mucin-polypeptide...