Djalil, Vella NurazizahElvyra, RozaRoslim, Dewi Indriyani2016-01-302016-01-302016-01-30wahyu sari yenihttp://repository.unri.ac.id/xmlui/handle/123456789/7829Riau Province has the typical of floodplain river. One of the fish that live in this river ecosystem is Kryptopterus limpok. Information of molecular barcodes of mitochondrial cytochrome c oxydase subunit 3 (COX3) gene from K. limpok is still unknown. The objective of this research was to obtain the DNA fragment of the mitochondrial COX3 gene K. limpok from Kampar River, Tapung River, and Indragiri Hulu River. Total DNA isolated were taken from the muscle of fish-tail. The total DNA was electrophoresed on 1,2% agarose gel and then visualized using UV transiluminator (WiseUv WUV-M20, Daihan Scientific). PCR amplification was performed using a primer pair of COXIIIF1 (forward) 5’GCT TAG GTT TCA CCA CAA GA3’ and COXIIIR1 (reverse) 5'CGA ACA CAA ATC AGT GGT GTT CT3'. PCR condition based on Elvyra dan Duryadi (2007) with modification. Total DNA concentrations produced ranging from ±300 ng/μl and the fragment length of the mitochondrial COX3 gene K. limpok was 660 bpenAmplificationDNAElectrophoresisKryptopterus limpokPCRstudent Paper Post Degree