10.22376/ijpbs.2019.10.1.p1-12 Volume 4 Issue 3 2013 (July - September) The present study deals with the identification, isolation and lessThan i greaterThan in silico lessThan /i greaterThan characterization of gene encoding geraniol dehydrogenase from lessThan i greaterThan Ocimum americanum lessThan /i greaterThan . Mature leaves of plants have a higher degree of secondary metabolites that hampers the nucleic acid isolation, PCR amplification and other downstream reactions. The DNA isolation from mature leaves of lessThan i greaterThan O. americanum lessThan /i greaterThan is described here which involves a modified cetyl trimethyl ammonium bromide extraction protocol (3.5%) with high salt concentration to remove polysaccharides, 3% poly vinyl pyrrolidone to remove polyphenols and an extended RNase treatment. This protocol yielded genomic DNA having high quality as well as quantity. Gene specific primers were designed using Primer3 tool, amplified through PCR and sequenced. lessThan i greaterThan In silico lessThan /i greaterThan characterization and annotation of geraniol dehydrogenase was completed by web based tools. The newly constructed 1647 bp length sequence was submitted in NCBI (GenBank Id: JQ765502.1) and named lessThan i greaterThan Ocimum americanum lessThan /i greaterThan geraniol dehydrogenase ( lessThan i greaterThan OaGDH lessThan /i greaterThan ) gene. AAKANKSHA WANY, ASHUTOSH KUMAR, VINOD KUMAR NIGAM AND DEV MANI PANDEY Cetyl trimethyl ammonium bromide, Geraniol dehydrogenase, Iterative threading assembly refinement, Poly vinyl pyrrolidone 365-379