They can make nucleic acid recovery quantitative and are especially important when working with small amounts of critical RNA or DNA samples. All of Ambion's coprecipitants are guaranteed to be nuclease-free so that there is no risk of introducing nucleases into your precious samples during precipitation.
GlycoBlue™ consists of glycogen a branched chain carbohydrate covalently linked to a blue dye. Because glycogen does not contain appreciable amounts of nucleic acids, it is preferable to yeast RNA as a coprecipitant, especially when nucleic acid mass will be assessed or in applications where added nucleic acid could interfere with subsequent enzymatic reactions. GlycoBlue not only facilitates nucleic acid recovery during precipitation, but its blue color greatly increases visibility of small nucleic acid pellets after precipitation. Glycogen with no attached dye is also available.
Linear Acrylamide is chemically synthesized and is thus not derived from any biological material, making it the recommended coprecipitant for RT-PCR applications.
Yeast RNA and Yeast tRNA are also available. Purified Yeast Total RNA and Yeast tRNA are also suitable as coprecipitants in many nucleic acid precipitations. However, they should not be used in reactions inhibited by exogenous RNA.