Titration methods for detecting polyvinyl sulfonate (pvs) in buffers
AssigneeAmgen Inc.
InventorRobert Joseph Soto
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Abstract
The disclosure provides methods, including automated methods, to detect levels of polyanions such as polyvinyl sulfonates in fluids such as buffers by complexometric or titration-based techniques. Such polyanionic compounds have been shown to inhibit enzymes involved in PCR that confounds efforts to monitor the purity of proteins obtained from cell culture, such as biologies and biosimilars.
Claims31
A titration method for detecting a polyanionic enzyme inhibitor in a fluid comprising:
- (a) contacting a fluid with a known quantity of a polycationic compound;
- (b) contacting the material in (a) with an indicator compound, wherein the indicator compound exhibits a changed property in the free form compared to its form when complexed to a polycationic compound, and wherein sufficient indicator compound is added to detect the free form of the indicator compound in the absence of complex formation;
- (c) repeating (a);
- and
- (d) detecting the free form of the indicator compound at the titration point, thereby detecting the polyanionic enzyme inhibitor.
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An automated titration method for detecting a polyanionic enzyme inhibitor in a fluid comprising:
- (a) combining a fluid and an indicator compound, wherein the indicator compound exhibits a changed property in the free form compared to its form when complexed to a polycationic compound, and wherein sufficient indicator compound is added to detect the free form of the indicator compound in the absence of complex formation;
- (b) contacting the material in (a) with a known quantity of a polycationic compound;
- (c) measuring the absorbance of the fluid comprising the indicator compound and polycationic compound using a titrator instrument;
- and
- (d) automatically repeating (b) and (c), wherein detection of the free form of the indicator compound detects the polyanionic enzyme inhibitor.
Dependencies are inferred from the claim text.