A modified IMAC method for the capture of target protein from mammalian cell culture harvest containing metal chelating species.

Although immobilized metal affinity chromatography (IMAC) offers high capacity and protein selectivity it is not typically used commercially for the capture of native proteins from mammalian cell culture harvest. This is due mainly to the potential for low target recovery due to the presence of strong metal ion chelating species in the harvest that compete for the metal immobilized on the resin. To address this issue a buffer exchange step, such as tangential flow filtration (TFF), is added after harvest clarification and prior to IMAC to remove the interfering harvest components.

Acute oral pain intensity and pain threshold assessed by intensity matching to pain induced by electrical stimuli.

Aims: To investigate a recently developed pain-intensity matching device (Painmatcher) in terms of reproducibility, pain intensity, and unpleasantness experienced by healthy individuals upon pain threshold assessment, as well as differences in pain threshold between genders and between healthy individuals and patients with acute oral pain, and the relation between pain-intensity assessments by the Painmatcher and a visual analog scale (VAS) in the patients.

Methods: Forty healthy individuals and 28 patients with acute oral pain participated. The Painmatcher produces an eventually noxious stimulus by increasing electrical impulses between 2 fingers.