Based on published genomic sequences and comparison with human CEACAM1 the 5'-and the 3'-untranslated regions of canine CEACAM1 were predicted and used to design primers for amplification of full length cDNA (CEACAM1cf-5i and CEACAM1cf-3i; Table 3 ). These primers introduced HindIII and XbaI restriction sites at the 5'-and 3'-ends of the PCR products, respectively. PCR was performed with cDNA from dog liver using Pfu DNA polymerase according to the protocol supplied by the manufacturer. After electrophoretic separation, 6 distinct ethidium bromide-stained DNA fragments were excised from the agarose gel and purified using the Perfectprep ® Gel Cleanup Kit (Eppendorf, Hamburg, Germany). The full length cDNAs were digested with HindIII and XbaI and cloned into the pRc/CMV expression vector. Plasmid DNA isolated from 12 clones were analyzed by PCR and sequencing. Full length cDNAs of CEACAM23, CEACAM24, CEACAM25, CEACAM28 and CEACAM30 were cloned using the TOPO TA Cloning ® Kit (Invitrogen Life Technologies). PCR was performed with cDNA from dog spleen using Taq polymerase (Qiagen) and the CfCEACAM1-5i-f forward primer for all CEACAMs combined with gene-specific reverse primers from the 3'untranslated regions (UTR; Table 3 ).