Fig. 5. (A) Real-time PCR assay for the relative expression of crayfish Procambarus clarkii ECaC mRNA in postmolt hepatopancreas, gill and antennal gland. Expression in postmolt cardiac and axial muscle was undetectably low relative to expression in epithelial tissues and so data were not included. Relative quantification (RQ expressed as mean ± s.d. from three different samples with 4-5 crayfish in each sample) was performed by normalizing the Ct value of each sample with the Ct value of the endogenous control (18s rRNA gene, Ct), and finally calculated using Ct of control (hepatopancreas) as calibrator. (B) Quantitative RT-PCR showing distribution of Procambarus clarkii ECaC (upper panel) and 18s rRNA (lower panel) in a range of postmolt crayfish tissues.