RNA separations

RNA Separation by Non-Denaturating Sucrose Density Gradient Centrifugation... 

Like plants, bacteria have a rigid cell wall. Hence appropriate measures are taken to weaken or break the cell wall before the cells are lysed for the extraction of RNA. Separate methods [10] exist for gram-negative or grampositive bacteria because of differences in their cell compositions. 

A technique similar to the southern blot. RNA separated by electrophoresis is transferred to a PDVF membrane. Specific RNA sequences are detected... 

The so-called micro-total analytical systems (/tTAS) can integrate sample handling, separation, and detection on a single chip [9]. Postcapillary reaction detectors can be incorporated as well [10]. Fluorescence detection is the most common method employed for these chip-based systems. A commercial instrument (Agilent 2100 Bioanalyzer) is available for DNA and RNA separations on disposable chips using a diode laser for LIF detection. In research laboratories, polymerase chain reaction (PCR) has been integrated into a chip that provides size separation and LIF detection [11]. 

Southern s technique could not be applied to the blot transfer of RNA separated by gel electrophoresis. Alwine et al. (A2) therefore devised a procedure in which RNA bands are blot transferred from the gel onto the chemically reactive paper, where they are bound covalently. The reactive paper is prepared by diazotization of aminobenzyl oxymethyl paper, which can be prepared from Whatman paper by a series of uncomplicated reactions. Once covalently bound, the RNA is available for hybridization with radiolabelled DNA probes. Hybridizing bands are detected autoradiographically. This method is termed Northern blotting. 

Livengood, A. J., Zaug, A. J., and Cech, T. R. (2002). Essential regions of Saccharomyces cerevisiae telomerase RNA separate elements for... 

The splicing also depends on small nuclear ribonucleoproteins, or snRNPs (pronounced snurps ), to mediate the process. This snRNP is another basic type of RNA, separate from mRNA, tRNA, and rRNA. The snRNPs, as their name implies, contain both RNA and proteins. The RNA portion is between... 

Chang CS, Ni HS, Suen SY, Tseng WC, Chiu HCh, Chou CP. Preparation of inorganic-organic anion-exchange membranes and their application in plasmid DNA and RNA separation. J. Membr. Sci. 2008 311 336-348. 

A number of modern HPLC columns have been used for DNA and RNA separations. One example is a silica-based C18 material available from Varian Corporation (Walnut Creek, CA). There have been recent reports on monolith polymeric materials providing excellent separations [30-32]. The remarkable performance of the DNA and RNA separation columns is based on a number of properties including the porosity of the packing material, its polarity, the absence of metal contamination, and the small size and narrow size distribution of the packing material. 

The fluid entering the oven compartment is normally cooler than the oven and there is a time lag before this new fluid comes to the oven temperature. In most HPLC ovens, the fluid never does reach the set point of the oven. In DNA and RNA separation instrumentation, a pre-heat tube is used to bring the fluid to column temperature before it reaches the column. The oven temperature should be accurate, should not drift and should be precise, i.e. it should come to the same temperature each time it is directed by the run method to go to a specific temperature. 

These results indicate that the poliovirus RF-RNA served as a template for the synthesis of RNA complementary to viral RNA (i.e. minus-strand RNA). Separated poliovirus minus- and plus-strand RNAs anneal with an efficiency of 60 % under our experimental conditions (RNA concentrations of 5 (xg/ml, assay of RNase resistance with Tj RNase and RNase I). This value is considerably lower than that found with reovirus (Shatkin and Banerjee, 1970) or phage RF-RNA (Bishop and Levintow, 1971). Part of the reannealed poliovirus RNA is found in a structure resembhng RI-RNA (Bishop and Levintow, 1971) (Koch and Vollertsen, unpubhshed). Therefore, the estimate of the synthesis of pohovirus-specific RNA in E. coli determined by RNase resistance of the annealed RNA represents only a minimal... 

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