GlycoBlue (15 mg/ml) from Life Technologies

Ambion® GlycoBlue™ consists of a blue dye covalently linked to glycogen, a branched chain carbohydrate, and is useful as a nucleic acid coprecipitant. Ideal coprecipitant in nuclease protection assays at 1⁄100 dilution of stock solution, it is provided in one tube containing 0.3 mL at a concentration of 15 mg⁄mL.

• Ideal for RT-PCR
• Increases pellet mass
• Quantitative recovery of low concentrations (ng⁄mL) of nucleic acid
• Prevents pellet loss in nuclease protection assays

What is a Coprecipitant?
Coprecipitants are inert substances used to aid recovery of nucleic acids during alcohol precipitations. While they can be used for precipitating large amounts of nucleic acids, they are essential for quantitative recovery of small amounts of nucleic acids in dilute solutions. Often, the use of such molecules is desirable for no other reason but visualization of the pelleted precipitate after centrifugation.

GlycoBlue™ can be added to nucleic acid solutions at a final concentration of 50–150 μg⁄mL. When a typical acetate⁄alcohol precipitation is done, the GlycoBlue™ will precipitate with the nucleic acids, facilitating good RNA or DNA recovery while increasing the size and visibility of the pellet. Since glycogen does not contain appreciable amounts of nucleic acids, it is often preferable to yeast RNA as a coprecipitant, especially in applications where nucleic acid mass is being assessed or where added nucleic acid could interfere or compete with subsequent enzymatic reactions.

Ambion® glycogen (used in GlycoBlue™) is isolated from mussel, a biological source, as are most other preparations of this coprecipitant. Glycogen is treated with Proteinase K and SDS to remove any contaminating nucleases, and then phenol⁄chloroform extracted, ethanol precipitated, and resuspended in nuclease-free water. The glycogen is guaranteed RNase- and DNase-free.