Channeling block

A vacuum-manifold accessory from QIAGEN, the Channeling Block is supplied for use with the QIAvac 96 during manual purification of 6xHis-tagged proteins from E. coli, as set out in the manufacturer's supplementary protocol for the Ni-NTA Superflow 96 BioRobot Kit. The product sits within QIAGEN's Primary Sample Technology portfolio.

In both the native-conditions and denaturing-conditions vacuum protocols, the Channeling Block is placed into the QIAvac base beneath the Ni-NTA QIAfilter 96 Plate after cleared lysates have been loaded. A weak vacuum of approximately –100 mbar is then applied for approximately 5 min, or until all samples have been drawn completely through the plate. According to the manufacturer, using a weak vacuum in this configuration extends the time available for binding of the 6xHis-tagged proteins to the Ni-NTA matrix, allowing more efficient binding and higher yields. The protocol notes that although some wells may pass buffer earlier than others, this does not affect elution or yield.

Before the elution step with Buffer NPI-250, the Channeling Block is removed from the QIAvac base so that the chosen 96-well elution vessel can be positioned inside the base to collect the eluted protein.