Search results
Results From The WOW.Com Content Network
Percoll is a reagent consisting of colloidal silica particles used in cell biology and other laboratory settings. It was first formulated by Pertoft and colleagues, [2] and commercialized by Pharmacia Fine Chemicals. [3] Percoll is used for the isolation of cells, organelles, or viruses by density centrifugation.
Some density-gradient work for purifying cells and organelles can be carried out in swinging-bucket rotors, or in the case of Percoll gradients in fixed-angle rotors. [9] High-speed or superspeed centrifuges can handle larger sample volumes, from a few tens of millilitres to several litres.
Differences between differential and density gradient centrifugation [ edit ] The difference between differential and density gradient centrifugation techniques is that the latter method uses solutions of different densities (e.g. sucrose , Ficoll , Percoll ) or gels through which the sample passes.
The Prewitt operator is used in image processing, particularly within edge detection algorithms. Technically, it is a discrete differentiation operator, computing an approximation of the gradient of the image intensity function.
An example of such a product is the "Accuspin System Histopaque-1077" sold by Sigma Aldrich. The cost of this product is significantly higher than basic Ficoll and Ficoll-Paque products. It is also possible to have the Ficoll-Paque separating system included in the Vacutainer used to collect the blood.
A binding gel, diffusive gel (typically a polyacrylamide hydrogel) and filter membrane are stacked onto the base, and the cap is used to seal the gel and filter layers inside [4]: 4.2.3 Dimensions of the gel layers vary depending on features of the environment, such as the flow rate of water being sampled; [4]: 4.2.1 an example is an ...
Conjugate gradient, assuming exact arithmetic, converges in at most n steps, where n is the size of the matrix of the system (here n = 2). In mathematics, the conjugate gradient method is an algorithm for the numerical solution of particular systems of linear equations, namely those whose matrix is positive-semidefinite.
The transport rate is usually estimated using the equations of Stokes flow, where the fluid velocity is obtained by equating the stress gradient to the viscous dissipation. A surface tension is a force per unit length, so the resulting stress must scale as Δ γ / L {\displaystyle \Delta \gamma /L} , while the viscous stress scales as μ u / L ...