In general, it is possible to use DNA probes for northern blots (PCR or random-primed DNA probes). It is however important to keep in mind that DNA probes are best detecting abundant messages, such as housekeeping genes.
An introduction to both Northern and Southern blotting, popular methods for the transfer of macromolecules to membranous support. This article also offers a Southern blot protocol and a northern blot protocol.
Dextran sulfates are supplied as the sodium salt forms, making them soluble and stable in water. Dextran sulfate contains approximately 17% sulfur which is equivalent to approximately 2.3 sulfate groups per glucosyl residue.