title: Isolation of high quality RNA from cereal seeds containing high levels of starch.
abstract: BACKGROUND
  Cereals are an important source of food, feed and fuel with a rapidly increasing global demand. However, cereal seeds contain high levels of starch and polysaccharides, making the isolation of high quality RNA extremely difficult.
  
  
  OBJECTIVE
  To develop a novel method for extracting high quality total RNA from various starch- and polysaccharides-rich cereal seeds, such as maize, rice, sorghum and wheat.
  
  
  METHODS
  We developed a modified sodium dodecyl sulphate (SDS)/TRIzol method. The combined use of a Tris buffer (pH 9.0) and SDS before TRIzol extraction effectively resolved the problem of seed homogenate solidification in such a buffer. A high concentration of SDS was used separately, not only to promote cell lysis but also to effectively dissolve seed sample containing high levels of starch. Moreover, acid phenol saturated with 0.1  M citrate buffer (pH 4.3) was used to separate RNA from DNAs, proteins and high levels of starch. This rapid protocol was compared with other RNA isolation methods preferentially used for plants rich in polysaccharides and secondary metabolites.
  
  
  RESULTS
  Gel electrophoresis analysis indicated that the extracted total RNA had good integrity without apparent DNA contamination. Furthermore, an A₂₆₀/₂₈₀ ratio of approximately 2.0, an A₂₆₀/₂₃₀ ratio of more than 2.0 and RIN values of more than 8.6 indicated that the isolated RNA was of high purity. The isolated RNA was suitable for subsequent molecular manipulations, such as reverse-transcription polymerase chain reaction (PCR), rapid amplification of cDNA ends (RACE) and real-time PCR.
  
  
  CONCLUSIONS
  The study has described an easy, efficient and highly reproducible method for RNA isolation from various cereal seeds.
authors: Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, No. 333 Nanchen Road, Shanghai, P.R. China.
authors: Guifeng
authors: G
authors: Wang
authors: Gang
authors: G
authors: Wang
authors: Xiaowei
authors: X
authors: Zhang
authors: Fang
authors: F
authors: Wang
authors: Rentao
authors: R
authors: Song
mesh_terms: D002523:Edible Grain / Q000737:chemistry / Q000235:genetics*; D004587:Electrophoresis, Agar Gel; D006146:Guanidines; D006863:Hydrogen-Ion Concentration; D012275:Oryza / Q000737:chemistry / Q000235:genetics; D010636:Phenols; D011134:Polysaccharides / Q000302:isolation & purification / Q000378:metabolism; D018749:RNA, Plant / Q000302:isolation & purification*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000737:chemistry / Q000235:genetics*; D012967:Sodium Dodecyl Sulfate; D045868:Sorghum / Q000737:chemistry / Q000235:genetics; D013213:Starch / Q000302:isolation & purification* / Q000378:metabolism; D014908:Triticum / Q000737:chemistry / Q000235:genetics; D014325:Tromethamine; D003313:Zea mays / Q000737:chemistry / Q000235:genetics
chemical_list: D006146:Guanidines; D010636:Phenols; D011134:Polysaccharides; D018749:RNA, Plant; C411644:trizol; D014325:Tromethamine; D012967:Sodium Dodecyl Sulfate; D013213:Starch