Effect of gelation conditions on the gel structure and resolving power of agarose-based DNA sequencing gels

Abstract

The effect of gelation conditions on the structure and resolving properties of agarose-based DNA sequencing gels were studied. Gels that were formed by rapid cooling gave separation patterns with sharp, well-defined bands, and resolved base repeats that were not separated on gels which were allowed to cool slowly. Analyses by electron microscopy indicated that the rapidly cooled gels have a homogeneous pore structure with a smaller average pore size than gels that were cooled slowly. The two types of gels also differ in optical clarity, and have significant differences in their melting characteristics as measured by differential scanning calorimetry.

Dynamic Rheology of Agar Gel Based Aqueous Binders

“…In addition, the relaxation spectrum, H(), of the gels was approximated using Eq. (8). The results indicate that the relative contribution from each relaxation process does not change significantly with agar content.…”

“…[3][4][5][6][7][8][9] Recent studies 10 -15 have reported the successful use of high solids loading (Ͼ60 vol%) agar gel based aqueous binders in powder consolidation methods such as gelcasting and powder injection molding. Agar binders have the potential for fabrication of parts with large cross sections, as well as extensive variations in thickness, within one part.…”

Thermal Phase Transitions of IOTA Carrageenan in CaCl2 Solutions: A Fluorescence Study

“…[3] For example, the kinetics and equilibrium processes of the sol-gel transitions of agar or agarose gels as well as the effect of gelation conditions on the gel's microstructure and rheological properties, have been studied in past few years. [20][21][22] It was observed that gelation of agar molecules results in a large sigmoidal increase in the magnitude of the sol's shear modulus. [23,24] On reheating, the gel structure is destroyed and during the gel-sol transition, the shear modulus follows another sigmoidal path back to its initial value, forming a hysteresis loop.…”

A fluorescence study on the gel-to-sol transition of κ-carrageenan

“…The kinetics and equilibrium processes of the phase transitions of agar or agarose gels as well as the effect of gelation conditions on gel's microstructure and rheologic properties have been studied in past [7][8][9]. It was observed that gelation of agar molecules results in a large sigmoidal increase in the magnitude of the sol's shear modulus [10,11].…”