When many RNA samples are to be processed or when working with small amounts (<50 µg) of total mammalian RNA, the technique of choice is batch chromatography on oligo(dT)-cellulose. The method described in this protocol uses a combination of temperature and ionic strength to maximize binding and recovery of polyadenylated RNA. IMPORTANT: Prepare all reagents used in this protocol with Diethyl pyrocarbonate (DEPC)-treated H2O. Joseph Sambrook and David W. Russell. - [Read Selection of Poly(A)+ RNA by Batch Chromatography - Subscription Required]
DEAE-dextran is generally used to obtain a burst of transient expression of cloned genes after transfection of mammalian cells. Many variants of the technique have been described, all of which seek to maximize the uptake of DNA and to minimize the cytotoxic effects of DEAE-dextran. In this protocol cells are exposed briefly to a high concentration of DEAE-dextran-DNA and then to chloroquine diphosphate, which is a facilitator of transfection. - [Read Transfection Mediated by DEAE-Dextran: High-efficiency Method Protocol]