Monitoring of Compounds

Abstract

The present invention relates to methods for determining the change in concentration of a substance in solution over time by continuously monitoring in real time. In particular, the present invention relates to methods for continuously monitoring the concentration of compounds during the manufacturing process of biomolecules.

1 . A method of evaluating a substance in solution over time, comprising:
 continuously monitoring in real time an ultraviolet spectrum of the substance by:
 measuring the ultraviolet spectrum in a flow-through mechanism comprising a light source, an optical fiber, and a detector, wherein light from the light source is emitted by the optical fiber and defines a pathlength between the optical fiber and the detector, wherein the pathlength is dynamically altered by moving the optical fiber to achieve a plurality of dynamically variable pathlengths such that multiple measurements of the ultraviolet spectrum are made at the dynamically variable pathlengths between the optical fiber and the detector, and wherein the pathlength is dynamically altered so that a characteristic of the substance is determinable without dilution or concentration of the solution; 
 determining the characteristic of the substance based on said measured ultraviolet spectrum; 
 comparing the characteristic of the substance at a first time with the characteristic of the substance at a second time; and 
 based on the comparison, adjusting a biotechnology process. 
   
     
     
         2 . The method of  claim 1 , wherein adjusting the biotechnology process comprises adjusting a mixing of the solution, adjusting operation of a pump, adjusting a pH of the solution, adjusting a tangential flow filtration. (TFF) process, adjusting a chromatography process, adjusting an ultrafiltration process, adjusting a diafiltration process, or combinations thereof. 
     
     
         3 . The method of  claim 1 , wherein adjusting the biotechnology process adapts a process device behavior based on at least one of a wavelength, a path length, a data acquisition mode for wavelength and/or path length, kinetics, a trigger and/or a target, a discrete path length and/or wavelength band for provide different dynamic ranges/resolutions for different areas of a spectrum, a cross sectional plot representing an absorbance and/or a path length curve, a regression algorithm and/or a slope determination, a concentration determination from one or more slope values, an extinction coefficient determination, a baseline correction, and a scatter correction. 
     
     
         4 . The method of  claim 1 , wherein adjusting the biotechnology process adapts a scanning and/or a discrete wavelength read option, a signal averaging time, a wavelength interval, a scanning and/or a discrete path length read option, a baseline correction, scatter correction, a real-time wavelength cross-section, a wavelength threshold option, a path length threshold option, an absorbance threshold option, an absorbance option, a slope option, an intercept option, a coefficient of determination option, or a kinetic and/or continuous measurement option. 
     
     
         5 . The method of  claim 1 , wherein said determining and comparing steps comprise characterizing solutions including yeast fermentations, bacteria, insect cell cultures, mammalian cell cultures, and protein expressions. 
     
     
         6 . The method of  claim 1 , wherein said measuring step comprises a plurality of measurements per minute, wherein each of said plurality of measurements provide quantification or one or more substances in said solution. 
     
     
         7 . The method of  claim 1 , further comprising, based on said determining and comparing steps, identifying a chromatography column to be out of specification by determining an output flow of the chromatography column, and wherein said adjusting a biotechnology process comprises re-routing outflow of the to another chromatography column for re-purification. 
     
     
         8 . The method of  claim 1 , further comprising, based on said determining and comparing steps, comparing at least one of a current process and a current output to historical information, and using said comparison to improve or alter the process either after or while the biotechnology process is running. 
     
     
         9 . The method of  claim 1 , wherein the characteristic of the substance comprises a concentration, and wherein the solution is subjected to one or more purification processes including but not limited to precipitation, filtration, electrophoresis, chromatographic separation, chemical reactions and combinations thereof. 
     
     
         11 . The method of claim  10 , wherein chromatographic separation comprises anion exchange chromatography, cation exchange chromatography, gel filtration chromatography, hydrophobic interaction chromatography, or affinity chromatography. 
     
     
         12 . The method of  claim 1 , wherein said a flow through mechanism is disposed at an outlet of a chromatography column. 
     
     
         13 . The method of  claim 1 , wherein the characteristic of the substance comprises a concentration of the substance, a titer of the substance, a homogeneity of the substance, or a mass of the substance. 
     
     
         14 . The method of  claim 1 , wherein the characteristic of the substance is used to determine a binding capacity of a chromatography column. 
     
     
         15 . The method of  claim 1 , wherein the characteristic of the substance is used to determine a fouling condition of a tangential flow filter (TFF). 
     
     
         16 . The method of  claim 1 , wherein the comparing step is used to monitor a concentration of the solution as said concentration increases. 
     
     
         17 . The method of  claim 16 , further comprising, based on the concentration increase, determine a changing process phase of said biotechnology process. 
     
     
         18 . The method of  claim 1 , wherein the determining step comprises determining absorbance contributions of a plurality of components within the solution. 
     
     
         19 . The method of  claim 1 , wherein the determining and comparing steps comprise monitoring growth of a bacteria in the solution. 
     
     
         20 . The method of  claim 19 , wherein the bacteria is E. coli. 
     
     
         21 . A method of determining the change in concentration of a mixture comprising a plurality of substances in solution over time comprising:
 monitoring in real time the ultraviolet spectra of the plurality of substances at discrete time points by:
 measuring the ultraviolet spectrum in a flow-through mechanism comprising a light source, an optical fiber, and a detector, wherein light from the light source is emitted by the optical fiber and defines a pathlength between the optical fiber and the detector, wherein the pathlength is dynamically altered by moving the optical fiber to achieve a plurality of dynamically variable pathlengths such that multiple measurements of the ultraviolet spectrum are made at the dynamically variable pathlengths between the optical fiber and the detector, and wherein the pathlength is dynamically altered so that characteristics of the plurality of substances are determinable without dilution or concentration of the solution; 
 determining a characteristic of each of the plurality of substances based on said measured spectra; and 
 comparing the characteristics of the substances at the discrete time points. 
   
     
     
         22 . The method of  claim 21 , further comprising generating a control signal in response to the comparison, wherein the control signal adjusts a biotechnology process based on changing process conditions indicated by the comparison. 
     
     
         23 . The method of  claim 21 , wherein the characteristic of each of the plurality of substances comprises a concentration of each of the plurality of substances. 
     
     
         24 . The method of  claim 21 , wherein the characteristic of the substance is monitored at a plurality of locations within a biotechnology process system.