title: DNA isolation protocol for the medicinal plant lemon  balm (Melissa officinalis, Lamiaceae).
abstract: Lemon balm (Melissa officinalis) is a medicinal  plant that is widely used as a sedative or calmant, spasmolytic and  antibacterial agent and sleep aid. This has led to a high demand for lemon balm  products, resulting in the extinction of this species in some of its natural  habitats. Molecular techniques have increasingly been used in plant diversity  conservation and isolation of PCR amplifiable genomic DNA is an important  pre-requisite. Lemon balm contains high levels of polyphenols and  polysaccharides, which pose a major challenge for the isolation of high-quality  DNA. We compared different genomic DNA extraction protocols, including  traditional phenol-chloroform DNA extraction protocols and two commercial kits  for DNA purification for their ability to produce good-quality DNA from fresh  leaves of five lemon balm genotypes. Quality and quantity of the DNA samples  were determined using 0.8% agarose gel electrophoresis and a spectrophotometer.  The DNA purity was further confirmed by PCR amplification using barley  retrotransposon LTR base primers. The spectral quality of DNA as measured by  the A(260)/A(280) ratio ranged from 1.46 to 2.37. The Fermentase genomic  DNA purification kit and the CTAB extraction protocol using PVP and ammonium  acetate to overcome the high levels of polyphenols and polysaccharides yielded  high-quality DNA with a mean A(260)/A(280) ratio of 1.87. The quantity of DNA and its PCR purity  were similar with all the protocols, but considering the time and cost required  for extraction of DNA from a large number of samples, the CTAB protocol using  PVP and ammonium acetate is suitable for lemon balm.
authors.affiliation: Department of Plant Breeding and Biotechnology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran.
authors.forename: S
authors.initials: S
authors.lastname: Ghaffariyan
authors.forename: S A
authors.initials: SA
authors.lastname: Mohammadi
authors.forename: S
authors.initials: S
authors.lastname: Aharizad
mesh_terms: D018744:DNA, Plant / Q000302:isolation & purification*; D031334:Melissa / Q000235:genetics*; D010946:Plants, Medicinal / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D018626:Retroelements
chemical_list: D018744:DNA, Plant; D018626:Retroelements