Concentrating and Desalting Nucleic Acids with Microconcentrators Protocol Ultrafiltration is an alternative to ethanol precipitation for the concentration and desalting of nucleic acid solutions. It requires no phase change and is particularly useful for dealing with very low concentrations of nucleic acids. This protocol describes the use of the Microcon cartridge, a centrifugal ultrafiltration device, to concentrate and desalt nucleic acid solutions.
Mapping RNA with Nuclease S1 Protocol Preparations of RNA containing an mRNA of interest are hybridized to a complementary single-stranded DNA probe. At the end of the reaction nuclease S1 is used to degrade unhybridized regions of the probe, and the surviving DNA-RNA hybrids are then separated by gel electrophoresis and visualized by autoradiography or Southern hybridization. Method used to quantitate RNAs, to map the positions of introns, and to identify the locations of 5' and 3' ends of mRNAs on cloned DNA templates.
Purification of Nucleic Acids by Extraction with Phenol:Chloroform Protocol Protocol describes the standard method for nucleic acid purification by extraction first with phenol:chloroform (optionally containing hydroxyquiniline at 0.1%) and then with chloroform to remove any remaining phenol. The procedure takes advantage of the fact that deproteinization is more efficient when two different organic solvents are used instead of one.