Percoll 密度梯度离心教程.pptVIP

Percoll 密度梯度离心教程 ppt课件 Percoll 密度梯度离心教程 ppt课件 2021/3/26 Percoll 密度梯度离心教程 ppt课件 Percoll density gradient centrifugation 2021/3/26 Percoll 密度梯度离心教程 ppt课件 Outline Principles Physical properties Storage Make and use density of Percoll Tips Protocol Instrument and operation References and applications Contrast(differential velocity centrifugation) 2021/3/26 Percoll 密度梯度离心教程 ppt课件 For biological particles, the ideal gradient medium has been described as one having the following characteristics: ? covers a sufficient density range for isopycnic banding of all biological particles of interest ? possesses physiological ionic strength and pH ? is iso-osmotic throughout the gradient ? has low viscosity ? is non-toxic ? will not penetrate biological membranes ? is supplied sterile and is resterilizable ? will form self-generated gradients by centrifugation at moderate g-forces ? is compatible with biological materials ? is easily removed from purified materials ? does not affect assay procedures ? will not quench radioactive assays 2021/3/26 Percoll 密度梯度离心教程 ppt课件 Principles of density gradient centrifugation ? 2021/3/26 Percoll 密度梯度离心教程 ppt课件 Separation by density (isopycnic centrifugation) Separation by size (rate zonal centrifugation) 2021/3/26 Percoll 密度梯度离心教程 ppt课件 Percoll – physical properties Percoll is available from GE Healthcare. Composition silica sol with nondialyzable polyvinylpyrrolidone (PVP) coating（由聚乙烯吡咯烷酮包裹的硅胶颗粒） Density 1.130 ± 0.005 g/ml Conductivity 1.0 mS/cm（电导率） Osmolality 25 mOsm/kg H2O（渗透压） Viscosity 10 ± 5 cP at 20°C（粘度） pH 9.0 ± 0.5 at 20°C Refractive Index 1.3540 ± 0.005 at 20°C（折射率） Percoll is non-toxic 1.0~1.3g/ml The viscosity of Percoll is lower in saline solutions at physiological ionic 2021/3/26 Percoll 密度梯度离心教程 ppt课件 Storage of Percoll Sterile and unopen----5 years When opened, Percoll should be stored below +8℃ If Percoll opened under non-sterile conditions, it can be frozen for up to 6minth