Immunofluorescence Analysis of 3D Collagen Cultures

Harvested tissues were fixed in 10% formalin and embedded in paraffin. Immunofluorescence analysis of tissue sections and cells seeded on coverslips was performed as shown previously [11 , 12 ]. Whole-mount immunofluorescence staining for 3D collagen cultures was performed, as shown previously [13 (link)]. The primary antibodies used in this study include PAF1 1:100 (Invitrogen Cat# PA5-115713), mouse PAF1 1:100 (In house developed) [3 (link)], YAP1 1:100 (Santa Cruz Cat# sc-271134), TEAD4 1:100 (Invitrogen Cat#PA5-41446), TEAD1 1:100 (Invitrogen Cat#PA5-106477), SOX9 1:200 (Sigma-Aldrich Cat# AMAB90795) and CK19 1:50 (DSHB Hybridoma Product TROMA-III). In some immunofluorescence experiments, conjugated lectins, PNA-Rhodamine 1:100 (Vector Cat# RL-1072), and DBA-FITC 1:100 (Vector Cat# FL-1031) were used to stain acinar and ductal cells. Fluorescent images were captured using an LSM 710 confocal microscope and analyzed using ZEN software.