4.2 DNA Isolation

Generally speaking, most tissue that we deal with including brain, blood, heart, liver, and even cell culture samples can be processed for DNA isolation. While different tissues will have their own processing protocols, they all need some of the same basic storage conditions. The two primary concerns for tissue being collected for DNA isolation is keeping them cold and keeping them dry. For samples that are being actively used, storage at 4°C is better to prevent damage from-freeze thaw cycles. Otherwise, samples can be kept at -20°C in a normal freezer, -80°C in an ultra freezer or -180°C in liquid nitrogen. While dehydrating the tissue samples with liquid nitrogen can be beneficial for long term sample storage, tissue is usually stored in a container with or without a solution such as Ethanol or DMSO. Blood is a special case, because it can clot, which causes downstream issues. Generally, blood is drawn by a special technician and immediately stored in Heparin or EDTA coated tubes to prevent clotting.