Finding a universal low‐viscosity polymer for DNA separation

Abstract

We have investigated the viscosity of different commercially available polymers in solution and found that dextran has a low viscosity compared to other polymers of comparable molecular weight and resolving power. This makes it a potentially useful matrix for DNA separation in capillary electrophoresis, where either short time or low pressure are preferred for matrix replacement. We showed that dextran performs well for the separation of oligonucleotides and double-stranded DNA fragments. Together with the well-known application for protein separation, this makes dextran a universal polymer for the separation of biological macromolecules.

Separation of double-stranded and single-stranded DNA in polymer solutions: I. Mobility and separation mechanism

“…Figure 1 shows the dependence of the electrophoretic mobility on DNA size (dsDNA and ssDNA) at an electric field strength of 210 V/cm and at polymer concentrations of 1%, 2%, 5% and 10% in ªshort chainº, ªmedium chainº and ªlong chainº pDMA (with ªlong chainº pDMA, we did not perform experiments at 10%, due to the rather high viscosity, > 10 000 mm 2 /s). In all cases, we can observe the usual sigmoidal curve on the double logarithmic mobility vs. size plot, in agreement with separation of dsDNA in agarose gels [26,32], ssDNA in polyacrylamide gels [33] or dsDNA in entangled polymer solutions [17,28].…”

“…(11.12) in [10] and Eq. (6) in [17], respectively, with a slightly different prefactor. However, note that the equations mentioned above are based on scaling laws and the prefactors cannot be given exactly.…”

Polymer sieving matrices in microanalytical electrophoresis

“…70,75,76 Especially, a variety of natural or synthetic celluloses were employed. 40,100 One important benet of these linear polymers in conventional CE is low UV absorbance (especially 214 nm) compared to LPA 70 thus allowing on-line UV detection of separated proteins without labor-intensive staining/destaining processes. However, the analytical sensitivity of UV absorbance is orders of magnitude poorer than limits offered by LIF detection.…”

Influence of the electrokinetic injection conditions on the separation of DNA fragments in capillary electrophoresis

“…For example, ultra-fast separations can be carried out in short capillaries and high electric fields 16 or a very large DNA size range can be separated with the appropriate mixture of polymers, 17 i.e., by manipulating electric field and concentrations it is possible to obtain any degree of base-pair resolution at any given DNA size. 18 After a systematic study of the separation matrices 19,20 and of the factors that are relevant for the DNA mobility and its migration mechanism, 21,22 Heller reviewed all the theoretical and empirical mechanisms of electrophoretic migration of DNA in CE. 23 A particular aspect of the analysis of DNA in CE is sample introduction.…”