Molecular weight and polydispersity of calf-thymus DNA: static light-scattering and size-exclusion chromatography with dual detection.
Plausible calf-thymus DNA molecular weight distribution can be obtained by size-exclusion chromatography with dual low-angle light scattering/refractometric detection at sufficiently low flow rate. The distribution extends over three decades of molecular weight and is characterized by weight average molecular weight M(w) = 8418000 and polydispersity index M(w)/M(n) = 5.2. After strongly scattering impurities had been removed from the sample using adsorption properties of the 3 mum mixed-cellulose-ester filter membranes, static light-scattering measurement in flow injection mode was feasible and gave M(w) = 8580000, corroborating the veracity of SEC results.
Porsch
Bedrich
B
Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic. porsch@imc.cas.cz
Laga
Richard
R
Horský
Jirí
J
Konák
Cestmír
C
Ulbrich
Karel
K
D000818:Animals; D002417:Cattle; D002850:Chromatography, Gel / Q000379:methods; D004247:DNA / Q000032:analysis* / Q000737:chemistry*; D008027:Light; D008970:Molecular Weight; D012542:Scattering, Radiation
D004247:DNA; C427203:calf thymus DNA