Some fish have ability to live in the wide salinity range. Nile Tilapia (Oreochromis niloticus) is one example of fish that can tolerate the changes of the salinity in the water. Transferrin is one of many factors that makes Nile Tilapia fish can live in very wide salinity range. In Indonesia, Nile Tilapia usually lived in freshwater area. The purpose of this research is to clone and sequencing transferrin gene in Indonesian Nile Tilapia fish (Oreochromis niloticus). The subject of this research are three variants of Nile Tilapia fish which represent the population of Nile Tilapia fish in Indonesia, which is GESIT, Red Nifi, and Selfam. The DNA was taken from caudal fin and extracted by Phenol Chloroform Isoamyl-alcohol (PCI) method. Transferrin gene was amplified using TRF F2 primer (TTGACAACTATRAMRCCTGC TYCC) and TRF R1 primer (CAGCSGTAAACACCTGACCT) which resulted 800 bp DNA fragment. The DNA fragment from the agarose gel is then cut and purified. Transferrin gene fragment was cloned using pGEM
-T easy plasmid and was transformed into E.coli DH5α using heat shocked method. The cells which have transferrin gene were extracted and then used to do the sequencing. The result of this research was the transferrin gene from three variants can be successfully cloned into E.coli DH5α and also successfully been sequenced. Those sequences information already submitted in the gene bank with accession code KT804150.1 for tilapia strain GESIT, KT804151.1 for strain Red Nifi, and KT804152.1 for strain Selfam. The sequence information of transferrin gene from three variants of Indonesian Nile Tilapia will be useful for the next research to develop the salinity tolerant of Nile Tilapia fish in Indonesia.