Goblet cells from rat and human conjunctiva were grown in organ culture as described previously (21 (link)–23 (link)). Pieces of minced tissue were placed in RPMI 1640 medium supplemented with 10% FBS, 2 mM glutamine, and 100 μg/ml penicillin-streptomycin. The tissue plug was removed after nodules of cells were observed. As described previously, cells were identified as goblet cells by the following characteristics: 1) morphology by light microscopy both bright-field and histochemical staining with Alcian blue/periodic acid–Schiff’s reagent (indicates secretory product); 2) positive staining with the lectin Ulex europaeus agglutinin type I (UEA-I) and Abs to MUC5AC (both stain secretory product) and cytokeratin 7 (stains cell body); and 3) negative staining with Ab to cytokeratin 4 and lectin Griffonia Bandeiraea simplicifolia (indicates stratified squamous cells). First-passage goblet cells were used in all experiments.