title: An improved CTAB-ammonium acetate method for total RNA isolation from cotton.
abstract: BACKGROUND
  Cotton is an important economic crop. Genetic, developmental and molecular studies of cotton require high-quality total RNA from different tissues. Due to the richness in polyphenols and polysaccharides, the Trizol-based methods and other commercial kits are unsuitable for RNA isolation from cotton. Available methods are generally laborious and time-consuming.
  
  
  OBJECTIVE
  To develop an easy, simple and rapid cetyltrimethylammonium bromide (CTAB)-ammonium acetate protocol that takes less time and obtains high yield and quality of RNA from polysaccharide- and polyphenol-rich cotton tissues.
  
  
  METHODS
  Based on the original CTAB protocol, we used phenol-chloroform and chloroform-isoamyl alcohol to remove proteins, polysaccharides and polyphenols, and ammonium acetate to precipitate RNA, reducing the incubation time prior to RNA precipitation. After adding ammonium acetate to precipitate RNA, all centrifugation steps (14000 × g) were carried out at 4°C to avoid degradation.
  
  
  RESULTS
  The procedure took only 1.5 h and was suitable for different cotton tissues. The A(260) : A(280) ratios ranged from 1.80 to 1.85 with clear 28 s and 18 s ribosomal RNA bands in 1.2% agarose gel. The isolated RNA was usable for downstream molecular studies, such as reverse transcription polymerase chain reaction (PCR) and real-time quantitative PCR.
  
  
  CONCLUSIONS
  The CTAB-ammonium acetate method is easy, rapid, low-cost and effective for high-quality RNA isolation from polysaccharide- and polyphenol-rich cotton tissues.
authors.affiliation: Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan, Shandong, 250014, PR China.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhao
authors.forename: Qi
authors.initials: Q
authors.lastname: Ding
authors.forename: Jun
authors.initials: J
authors.lastname: Zeng
authors.forename: Fu-Rong
authors.initials: FR
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Shou-Jin
authors.initials: SJ
authors.lastname: Fan
authors.forename: Xin-Qiang
authors.initials: XQ
authors.lastname: He
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry*; D003368:Gossypium / Q000235:genetics*; D018749:RNA, Plant / Q000302:isolation & purification*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000085:Acetates; D002593:Cetrimonium Compounds; D018749:RNA, Plant; C018824:ammonium acetate; D000077286:Cetrimonium