discontinuous Protocols

Category: Cell Biology and Cell Culture

Techniques on how to create gradients of iodixanol for the fractionation of mammalian cells. These gradients can be generated as pre-formed discontinuous or continuous gradients. These gradients are invariably run in swinging-bucket rotors in low-speed centrifuges. - [Read C2 Preparation of pre-formed iodixanol gradients for mammalian cells.]

Category: Cell Biology and Cell Culture

OptiPrep Application sheet C14 describes procedures for determining the density and sedimenting properties of any cell (of any size or density) using either a continuous or discontinuous gradient of iodixanol. This Application Sheet describes procedures aimed at isolating specifically a relatively low-density cell fraction from any tissue. - [Read C25 Isolation from spleen, thymus, pancreas, alveolar tissue and other tissues]

Category: Cell Organelle Protocols: Subcellular Fractionation Protocols

A number of density gradient strategies have been developed for the fractionation of human erythrocytes according to their age. As the cells age, so their density tends to increase; reticulocytes therefore tend to have the lowest densities. Reticulocytes have frequently been partially purified on discontinuous gradients of arabinogalactan; the actual density range being quite varied, from quite broad ones. - [Read Fractionation of Human Erythrocytes (Normal or Sickle) and Reticulocytes in Discontinuous Iodixanol]

Category: Cell Organelle Protocols: Subcellular Fractionation Protocols

Fractionation of (a) vacuolar and subvacuolar vesicles and (b) vacuole and cytoplasm-to-vacuole targeting (Cvt) vesicles from yeast spheroplasts in a pre-formed discontinuous iodixanol gradients. Protocol includes: Formation of yeast spheroplasts; Isolation and vesiculation of the vacuoles; Separation of the vacuolar and subvacuolar vesicles; Separation of vacuoles and Cvt vesicles from a yeast spheroplast lysate. - [Read Fractionation of Vacuolar and Subvacuolar vesicles and Vacuole and Cytoplasm-to-Vacuole Targeting]

Category: Cell Organelle Protocols: Subcellular Fractionation Protocols: Membrane Isolation Protocols

This protocol is concerned with the use of iodixanol gradients in an analytical mode to study the membrane localization of a particular protein or function. Continuous gradients are best suited to this task. One of the protocols described in this protocol starts with a discontinuous gradient, but since the gradient is centrifuged at 174,000g for 16 h it will become continuous by diffusion. - [Read Fractionation of Yeast Membranes in Pre-Formed Continuous Iodixanol Gradients]

Category: Cell Organelle Protocols: Subcellular Fractionation Protocols: Mitochondria Isolation Protocols

A discontinuous gradient of iodixanol is used in which the crude mitochondrial fraction is layered beneath the preformed gradient. In this protocol the osmolality of the gradient is approx 600 mOsm and the crude mitochondrial fraction is loaded in 40% iodixanol rather than 50% iodixanol. - [Read Isolation of Yeast Mitochondria in aPre-Formed Iodixanol Gradient]

Category: Cell Organelle Protocols: Subcellular Fractionation Protocols: Membrane Isolation Protocols

The first part of the isolation procedure is a flotation through a continuous iodixanol gradient; this gradient is essentially a resolving gradient in which the caveolin-rich vesicles are concentrated in the top third of the gradient, while the predominantly caveolin-poor vesicles band in denser regions. A second discontinuous gradient is essentially a concentration gradient to band the caveolin-rich vesicles sharply at an interface. - [Read Purification of Caveolae Membranes from a Plasma Membrane Fraction of Cultured Cells and Tissues]

Category: Cell Organelle Protocols: Subcellular Fractionation Protocols: Mitochondria Isolation Protocols

This protocol describes a discontinuous gradient, which resolves the mitochondria from both lighter and denser organelles. Because the centrifugation is carried out for 4 h, diffusion will create a partially continuous gradient and this probably contributes to the resolution of the mitochondria from the lighter lysosomes. - [Read Purification of Mammalian Liver Mitochondria by Flotation Through a Pre-formed Discontinuous Iodixan]

Category: Cell Biology and Cell Culture

Protocol for the recovery of a highly viable fraction for use in fertilization. Protocol uses an iodinated density gradient medium to adjust the density of the raw ejaculate to approx 1.170 g/ml by mixing with a high density medium (ρ >1.26 g/ml) and loading it beneath a discontinuous gradient. - [Read Purification of viable bovine spermatozoa of normal morphology.]