Combining Step Gradients and Linear Gradients in Density

Combining Step Gradients and Linear Gradients in Density.

Combining aqueous multiphase systems (AMPS) and magnetic levitation (MagLev) provides a method to produce hybrid gradients in apparent density. AMPS—solutions of different polymers, salts, or surfactants that spontaneously separate into immiscible but predominantly aqueous phases—offer thermodynamically stable steps in density that can be tuned by the concentration of solutes. MagLev—the levita...

Freeze-cutting of density gradients.

There are numerous techniques for sampling density gradients in experiments involving the preparative ultracentrifuge. Among the sampling procedures used are: drawing liquid samples from the top of the density gradient with modified pipettes (J. B. Sinclair et al., Phytopathology 47:372, 1957), displacement through the top of the density gradient (E. Huff, H. Oxley, and C. S. Silverman, J. Bact...

Distribution of arbovirus antigens in density gradients.

Aqueous multiphase systems of polymers and surfactants provide self-assembling step-gradients in density.

This Communication demonstrates the generation of over 300 phase-separated systems-ranging from two to six phases-from mixtures of aqueous solutions of polymers and surfactants. These aqueous multiphase systems (MuPSs) form self-assembling, thermodynamically stable step-gradients in density using a common solvent, water. The steps in density between phases of a MuPS can be very small (Δρ ≈ 0.00...

An automatic collector for density gradients