Color quantification of chemical test pads and titration of analytes can be performed under different lighting conditions. In one embodiment, the lighting condition is estimated under which a digital image is captured and utilized to select a set of reference colors from which the quantified color is compared to determine the titration. In another embodiment, a plurality of comparisons are made with different lighting conditions with the result having the highest confidence level being selected to determine the titration.

Color quantification of chemical test pads and titration of analytes can be performed under different lighting conditions. In one embodiment, the lighting condition is estimated under which a digital image is captured and utilized to select a set of reference colors from which the quantified color is compared to determine the titration. In another embodiment, a plurality of comparisons are made with different lighting conditions with the result having the highest confidence level being selected to determine the titration.

A μPAD may include a substrate comprising a substrate. The μPAD may further include a non-polar material printed on a surface of the substrate such that a portion the surface is exposed. The exposed portion may include a receiving area, a plurality of test areas, and a plurality of channels disposed between the receiving area and the test areas. The μPAD may further include colorimetric sensors respectively positioned in the test areas. The channel regions may be configured to receive an analyte solution from the receiving area and direct the analyte solution to the colorimetric sensors. A system may perform image processing on captured images of the μPAD to provide multiplexed analysis of analyte solutions applied to the μPAD.

A μPAD may include a substrate comprising a substrate. The μPAD may further include a non-polar material printed on a surface of the substrate such that a portion the surface is exposed. The exposed portion may include a receiving area, a plurality of test areas, and a plurality of channels disposed between the receiving area and the test areas. The μPAD may further include colorimetric sensors respectively positioned in the test areas. The channel regions may be configured to receive an analyte solution from the receiving area and direct the analyte solution to the colorimetric sensors. A system may perform image processing on captured images of the μPAD to provide multiplexed analysis of analyte solutions applied to the μPAD.

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.

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.

A method for determining a parameter includes forming a reaction mixture by adding a volume of a solution to a sample. The solution contains a substance acting as a reaction partner for the analyte, where the reaction partner enters into a chemical reaction with the analyte, forming a reaction product of the analyte. The volume of the solution is adjusted, based on measured values of a physical or chemical measurand which are detected during the addition of the solution in the reaction mixture and whose value depends on the concentration of the analyte or of the substance in the reaction mixture. A titration of the solution to be titrated is subsequently performed from which a quantity of the substance present in the reaction mixture after addition of the volume of the solution is determinable, and a value of the parameter is ascertained using the titration.

A method for determining a parameter includes forming a reaction mixture by adding a volume of a solution to a sample. The solution contains a substance acting as a reaction partner for the analyte, where the reaction partner enters into a chemical reaction with the analyte, forming a reaction product of the analyte. The volume of the solution is adjusted, based on measured values of a physical or chemical measurand which are detected during the addition of the solution in the reaction mixture and whose value depends on the concentration of the analyte or of the substance in the reaction mixture. A titration of the solution to be titrated is subsequently performed from which a quantity of the substance present in the reaction mixture after addition of the volume of the solution is determinable, and a value of the parameter is ascertained using the titration.

A reagent test paddle includes a contamination detection medium, a reference color bar, at least one chemical test medium, and a unique identifier. The contamination detection medium includes a reagent that changes color in the presence or when exposed to a hostile or inhospitable environment. Each chemical test medium includes a regent that is responsive to a respective analyte in a biological sample. The reference color bar includes reference color samples of different colors. The unique identifier, like a serial number, identifies the particular paddle and its chemical test medium so it can be uniquely and anonymously associated with a user. A method includes capturing and interpreting digital images of a biologically unexposed and subsequently exposed reagent test paddle at various delay times within an automatically calibrated environment; locating the paddle in a plurality of digital images, extracting the reference color bar and locating the contamination detection medium and chemical test medium in each digital image. Color changes of the chemical test medium and contamination medium are detected at various delay times after sample exposure. To determine validity of test results, the method further compares the detected colors of the contamination detection medium with predetermined colors expected for no contamination and contamination.

A reagent test paddle includes a contamination detection medium, a reference color bar, at least one chemical test medium, and a unique identifier. The contamination detection medium includes a reagent that changes color in the presence or when exposed to a hostile or inhospitable environment. Each chemical test medium includes a regent that is responsive to a respective analyte in a biological sample. The reference color bar includes reference color samples of different colors. The unique identifier, like a serial number, identifies the particular paddle and its chemical test medium so it can be uniquely and anonymously associated with a user. A method includes capturing and interpreting digital images of a biologically unexposed and subsequently exposed reagent test paddle at various delay times within an automatically calibrated environment; locating the paddle in a plurality of digital images, extracting the reference color bar and locating the contamination detection medium and chemical test medium in each digital image. Color changes of the chemical test medium and contamination medium are detected at various delay times after sample exposure. To determine validity of test results, the method further compares the detected colors of the contamination detection medium with predetermined colors expected for no contamination and contamination.