Methods and compositions for nucleic acid isolation

An aqueous composition comprising a polysaccharide comprising one or more units represented by Formula II:

• an isomer, a salt, a tautomer, or a combination thereof, wherein:
• R2 and R3 are independently H, optionally substituted C1-C8 alkyl, optionally substituted C3-C8 cycloalkyl, optionally substituted C3-C8 heterocycloalkyl, or optionally substituted C2-C20 heteroalkyl;
• and
• wherein the aqueous composition further comprises one or more of a lysis agent, a chelating agent, a chaotropic agent, a salt, a buffering agent, a surfactant, or a defoaming agent.

An aqueous composition comprising a polysaccharide comprising one or more units represented by Formula II:

• an isomer, a salt, a tautomer, or a combination thereof, wherein:
• R2 and R3 are independently H, optionally substituted C1-C8 alkyl, optionally substituted C3-C8 cycloalkyl, optionally substituted C3-C8 heterocycloalkyl, or optionally substituted C2-C20 heteroalkyl;
• wherein the polysaccharide is present at a concentration from about 0.1 μg/mL to about 1000 μg/mL;
• wherein the aqueous composition further comprises one or more of a lysis agent, a chaotropic agent, a salt, a buffering agent, a surfactant, and a defoaming agent;
• wherein the buffering agent is present at a concentration from about 10 mM to about 100 mM;
• and
• wherein the surfactant is present at a concentration from about 5 mM up to about 200 mM.