Table 2 Characteristics of primers, RT-PCR protocol and antibodies

Occludin

fw: GGCCATTGCCATTGTACTGGG rv: GGAACCGGCGTGGATTTATAGG 315 bp; 58°C

polyclonal rabbit anti-occludin antibody No. 71–1500 (Invitrogen, Carlsbad, CA, USA), Protease-retrieval, Final dilution: 1:50

Claudin-1

fw: ATGGTGGTTGGCATCCTCCTG rv: GGCCTTGGTGTTGGGTAAGAGG 344 bp, 58°C

polyclonal rabbit anti-Claudin-1 antibody No. 51–9000, clone JAY.8 (Invitrogen, Carlsbad, CA, USA), EDTA-retrieval, Final dilution: 1:50

Claudin-2

fw: TCTCTTGGCCTCCAACTTGTGGG rv: GCACTGGATGTCACCATCATGGC 259 bp, 60°C

polyclonal rabbit anti-Claudin-2 antibody No. 51–6100 (Invitrogen, Carlsbad, CA, USA), EDTA-retrieval, Final dilution: 1:50

ZO-1

fw: TCTGATCATTCCAGGCACTCGC rv: CCACATCTGGTTGCCAACTTGG 225 bp, 58°C

polyclonal rabbit anti-ZO-1 antibody No. 61–7300, (Invitrogen, Carlsbad, CA, USA, Protease retrieval, Final dilution: 1:30

ZO-2

fw: AGAGGACACGCCGAGCAGATTG rv: TCCCGACATCATTGCCACCAG 272 bp, 60°C

polyclonal rabbit anti-ZO-2 antibody No. 71–1400, (Invitrogen, Carlsbad, CA, USA, EDTA retrieval, Final dilution: 1:150

β-Actin

fw: CATGCCATCCTGCGTCTGGACC rv: ACATGGTGGTGCCGCCAGACAG 400 bp, 60°C

not performed

Standard protocol

95°C: 15 min; (94°C: 30s, 58°-60°C: 30s, 72°C: 30s) 40 cycles; 72°C: 5 min