Apparatus and methods for correcting for variable velocity in microfluidic systems
AssigneeCaliper Technologies Corp.
InventorsAnne R. Kopf-Sill, Andrea W. Chow, Claudia B. Cohen, Steven A. Sundberg, John Wallace Parce
Life of this patent
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Abstract
Electrokinetic devices having a computer for correcting for electrokinetic effects are provided. Methods of correcting for electrokinetic effects by establishing the velocity of reactants and products in a reaction in electrokinetic microfluidic devices are also provided. These microfluidic devices can have substrates with channels, depressions, and/or wells for moving, mixing and monitoring precise amounts of analyte fluids.
Claims116
A method for determining the rate or extent of a reaction or assay in a microfluidic system, comprising:
- converting a first reaction or assay component having a first velocity (U1) into a product having a second velocity (Up) in a microfluidic channel;
- determining at least one velocity selected from the group consisting of U1 and Up;
- determining the concentration of the reaction or assay product in a portion of the microfluidic channel, whereby determining the at least one velocity and the concentration of the reaction or assay product provides for determination of the rate or extent of the reaction or assay.
A method for determining the rate or extent of a reaction or assay in a microfluidic system, comprising:
- contacting a first reaction or assay component having a first velocity (U1) to a second reaction or assay component having a second velocity (U2) in a microfluidic channel, thereby permitting formation of a reaction or assay product with a third velocity (Up);
- determining at least one velocity selected from the group consisting of U1, U2, and Up;
- determining the concentration of the reaction or assay product in a portion of the microfluidic channel, whereby determining the at least one velocity and the concentration of the reaction or assay product provides for determination of the rate or extent of the reaction or assay.
A method for determining the rate or extent of a reaction or assay in an electrokinetic microfluidic system, comprising:
- providing an electrokinetic microfluidic device having a microfluidic channel;
- applying an electric field along the length of the microfluidic channel;
- contacting a first reaction or assay component having a first charge mass ratio (CM1) and a first velocity (U1) to a second reaction or assay component having a second charge mass ratio (CM2) and a second velocity (U2) in the microchannel, thereby permitting formation of a reaction or assay product with a third charge mass ratio (CMp) and a third velocity (Up);
- determining at least one velocity selected from the group consisting of U1, U2, and Up;
- determining the concentration of the reaction or assay product in a portion of the microfluidic channel, whereby determining the at least one velocity and the concentration of the reaction or assay product provides for a determination of the rate or extent of the reaction.
A method of determining concentration of a reaction or assay product (Cp) in a microfluidic device, the method comprising the steps of:
- (i) converting a labeled first reactant or assay component having a velocity (Ur) and a label (Lr), the labeled first reactant or assay component producing a signal (Sas) in a signal detection system, to a reaction or assay product comprising a label Lp, having a velocity (Up), wherein (Ur) does not equal (Up) and wherein Lp comprises component elements of Lr;
- and,
- (ii) detecting a resulting change in Sas, wherein the change in Sas is an indicator of Cp.
A method of detecting a product formed by contacting a first and second component of a reaction comprising:
- contacting the first and second reactant in a microfluidic channel, wherein the first reactant comprises a detectable label, thereby producing a product comprising 5 the detectable label, which product has a different electrokinetic mobility than the first or second reactant;
- flowing the product and any first or second reactant remaining in the channel subsequent to said contacting step past a detector, wherein the label on the first reactant and the label on the product comprise the same detectable moiety;
- and,
- determining at least one of:
- concentration of the product, rate of product formation, or amount of product produced.
A method of dispensing representative mixtures in a microfluidic system, comprising:
- (i) introducing a first mixture into a first microfluidic channel, the mixture comprising at least first and second materials;
- (iii) transporting the first and second materials through the first channel, wherein the first and second mixtures travel at different velocities in the channel;
- (iv) gating an aliquot of first and second materials into the second channel for a selected period of time, the relative amount of first and second materials in the aliquot being proportional to the flux of first and second materials in the first mixture in the first channel, thereby dispensing a representative mixture of the first and second components.
A method of correcting data in a microfluidic system for effects of stacking of charged molecules in a microfluidic channel comprising:
- injecting at least one labeled blank into the microfluidic channel;
- monitoring control signal from the labeled blank in the channel to determine the signal of the blank over time;
- and,
- subtracting the control signal of the blank over time from experimental data from an analyte in the microfluidic channel.
A method of correcting data in a microfluidic system for effects of stacking of charged molecules in a microfluidic channel comprising:
- injecting a series of labeled control molecules in discreet high-salt buffer control plugs into the microfluidic channel to characterize timing of the control plugs as they pass the detection point;
- creating a control label intensity versus time data mask file;
- and,
- correlating the label intensity versus time mask file to experimental data from an analyte in the microfluidic channel to determine which times from the experimental data correlate with a sample plug.
A method of regulating a flowing reaction in a microfluidic channel comprising:
- mixing a plurality of reaction components in a first buffer, thereby providing a mixture of reaction components;
- electrokinetically transporting the mixture of reaction components in a microfluidic channel, thereby permitting the mixture of reaction components to react;
- applying a reaction inhibitor to at least a portion of the reaction mixture, thereby inhibiting further reaction of the reaction components in the portion.
A microfluidic apparatus for determining a rate of formation of a moving analyte on an electrokinetic microfluidic substrate comprising:
- a microfluidic substrate holder for receiving a microfluidic substrate during operation of the apparatus, which substrate holder has a microfluidic substrate viewing region;
- an analyte detector mounted proximal to the substrate viewing region to detect the moving analyte in a portion of the substrate viewing region;
- and,
- a computer operably linked to the analyte detector, which computer determines the rate of formation of the analyte, correcting for the effects of the motion of the analyte.
A microfluidic apparatus for determining a rate of formation of a moving analyte on an electrokinetic microfluidic substrate comprising:
- a microfluidic substrate holder for receiving a microfluidic substrate during operation of the apparatus, which substrate holder has a microfluidic substrate viewing region;
- analyte movement means for imparting velocity to the analyte in a channel of the microfluidic substrate during operation of the apparatus;
- detection means for detecting the moving analyte in the substrate viewing region;
- and,
- correction means for correcting the observed rate of formation of the moving analyte for the effects of the velocity of the analyte, which means are operably linked to the means for detecting the moving analyte.
A microfluidic apparatus, comprising:
- a microfluidic substrate comprising a body having a top portion, a bottom portion and an interior portion;
- the interior portion comprising at least two intersecting channels, wherein at least one of the two intersecting channels has at least one cross sectional dimension between about 0.1 μm and 500 μm;
- a detection zone for detecting the analyte in at least one of the two intersecting channels, when the analyte is in motion;
- and,
- a data analyzer which determines a rate of formation of the analyte in motion, wherein the analyzer comprises a processor which calculates the flux or velocity of the analyte in the detection zone.
An apparatus for determining the concentration of a product in a non-fluorogenic format, comprising:
- conversion means for converting a labeled first reactant or assay component to a second labeled component;
- signal detection means for detecting signal amplitude from the labeled first reactant or assay component and second labeled component;
- concentration calculation means for calculating the concentration of the product by measuring a change in signal amplitude which results from converting the first reactant or assay component into the second labeled component.
An apparatus for determining the concentration of a product in a non-fluorogenic format, comprising:
- a microfluidic substrate holder for receiving a microfluidic substrate, the holder comprising a substrate viewing region;
- a signal detector mounted proximal to the substrate viewing region;
- a signal output processor which converts variations in signal amplitude from the signal detector into concentration measurements for at least one of a plurality of moving analytes comprising one or more labels which have the same signal output, which plurality of analytes are detected by the signal detector.
Dependencies are inferred from the claim text.