2D电泳和2D DIGE

二维电泳(2D电泳)在1975由O'Farrell and Klose年首次引入,现在它是分析从细胞、组织、其他生物样品中提取出来的复杂蛋白质混合物广泛应用的方法。

这项技术根据蛋白质在两次分离步骤中的两种独立的特性将蛋白质分开:(1)等电点聚焦(IEF)根据蛋白的等电点(PI)将蛋白分开,以及(2)SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)根据蛋白质的分子量(MW)将它们分离。

2-D电泳作为一种生物化学分离技术的能力在它引入时就已认识到。然而,由于大量分离技术、成像分析以及蛋白表征的开发,它的应用变得越来越重要。

应用包括:

  • 蛋白质组分析
  • 细胞分化研究
  • 在研究中检测疾病标志物
  • 癌症研究

    2-D荧光差异凝胶电泳(2-D DIGE)是2-D电泳的演变,解决了原始技术的一些缺点,这些缺点主要是不同凝胶间的变化经常导致多次重复地跑胶。

    这项技术的优点是可以运行一个内标作为每次分离的一部分,并且还允许您最多同时运行两个检测样品,节省时间和精力的同时提供更准确和可靠的结果。

Much of GE Healthcare's filtration media are available in either flat format or in encapsulated formats, such as syringe filters, capsule filters, and filtration microplates.

  • Flat filters: Circles or sheet format. Circles would normally be used in an appropriate filter holder.
  • Prepleated filters (only for cellulose papers): Prefolded/pleated filter paper circles for use in conical filter funnels.
  • Syringe filters: Small, encapsulated, disposable filter units intended for filtration of small sample volumes using a syringe.
  • Syringeless filters/filter vials: Encapsulated, disposable filter units for small volume sample preparation not requiring the use of a syringe to drive the filtration step.
  • Inline filters: Encapsulated, disposable filter units intended for connection to flexible tubing. Units are available for filtration of liquids and for air/gas applications.
  • Capsule filters: Disposable filter units incorporating pleated filter media for larger volumes of liquid and air/gas applications.
  • Filtration microplates: Microplates with incorporated filter media for simultaneous filtration of multiple samples.

 

Filter characteristics and typical properties

The selection of a laboratory filter depends on the conditions and objectives of your experiment or analytical procedure. The three most important characteristics of any laboratory filter are:

  • Particle retention efficiency
  • Fluid flow rate through the filter
  • Loading capacity

According to your particular application, other important filter characteristics may also require examination, for example wet strength, chemical resistance, purity, and ash level. 

Typical properties of filter papers and glass fiber filters

Membrane materials

Chemical compatibility chart of membranes and housings


Filtration Methods for flat filters

  Gravity Vacuum Pressure
Cellulose Filter Papers Suitable Suitable Not generally used
Glass Microfiber Not suitable Suitable Suitable
Membranes Not suitable Suitable Suitable


Maximum practical volumes of cellulose filter paper circle sizes (quadrant folded)

Volume (ml) 15 20 35 75 135 300
Filter Diameter (mm) 90 110 125 150 185 240

 

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