Quantitative lateral flow assays and devices
View Patent ↗This invention provides solid phase specific binding lateral flow assay methods, devices and kits for quantitating high and low molecular weight analytes. The methods and devices of the invention employ labelled reagents which are either analyte analogs or complementary specific binding pair members for the analyte and a novel arrangement of capture zones comprising immobilized specific binding substances for either the analyte or the labelled reagent to effect bound from unbound labelled reagent as a function of analyte concentration. The capture zones are disposed on a non-bibulous matrix defining a flow path from a sample receiving zone to the capture zone. The devices of this invention also include multilane flow paths and multiple capture zones to quantitate analyte.
1. A method of visually quantifying an amount of an analyte in a sample, wherein the analyte is a member of a specific binding pair (sbp member), comprising:
providing a lateral flow matrix which defines a flow path and which comprises in series, a sample receiving zone, a labeling zone, and a plurality of serially oriented capture zones, wherein the labeling zone comprises a diffusively bound labeled first sbp member that is complementary to or analogous to the analyte, and each of the capture zones comprises at least a second sbp member immobilized in the capture zones; the second sbp member being complementary to the analyte;
contacting the sample with the sample receiving zone, whereby the sample flows along the flow path;
observing a pattern of label that accumulates at the plurality of capture zones; and
correlating a pattern of label accumulated in the capture zones to the amount of analyte in the sample;
wherein the sample receiving zone comprises an amount of a third sbp member immobilized within the sample receiving zone and complementary to the analyte, the amount being sufficient to bind a threshold level of the analyte.
2. A method of determining an amount of an analyte in a sample, wherein the analyte is a member of a specific binding pair (sbp member), comprising:
providing a lateral flow matrix which defines a flow path and which comprises in series, a sample receiving zone, a labeling zone, and one a plurality of serially oriented capture zones, wherein the labeling zone comprises a diffusively bound labeled first sbp member that is complementary to the analyte, and each of the capture zones comprises at least a second sbp member immobilized in the capture zones, the second sbp member being analogous to the analyte;
contacting the sample with the sample receiving zone, whereby the sample flows along the flow path;
observing a pattern of labeled first sbp member that accumulates at the plurality of capture zones; and
correlating a pattern of label accumulated in the capture zones to the amount of analyte in the sample;
wherein the labeled first sbp member includes a visually detectable label;
wherein the sample receiving zone comprises an amount of a third sbp member immobilized within the sample receiving zone and complementary to the analyte, the amount being sufficient to bind a threshold level of the analyte.
3. A device for determining an amount of an analyte in a sample, wherein the analyte is a member of a specific binding pair (sbp member), comprising a lateral flow matrix which defines a flow path and which comprises in series:
a sample receiving zone;
a labeling zone; and
a plurality of serially oriented capture zones;
wherein the labeling zone comprises a diffusively bound labeled first sbp member that is complementary to or analogous to the analyte, and each of the capture zones comprises at least a second sbp member immobilized in the capture zones, the second sbp member being complementary to the analyte;
wherein the sample receiving zone comprises an amount of a third sbp member immobilized within the sample receiving zone and complementary to the analyte, the amount being sufficient to bind a threshold level of the analyte.
4. A device for determining an amount of an analyte in a sample, wherein the analyte is a member of a specific binding pair (sbp member), the device comprising a lateral flow matrix which defines a flow path and which comprises in series:
a sample receiving zone;
a labeling zone; and
a plurality of serially oriented capture zones;
wherein the labeling zone comprises a diffusively bound labeled first sbp member that is complementary to or analogous to the analyte, and each of the one or more capture zones comprises at least a second sbp member immobilized in the capture zone, the second sbp member being complementary to the analyte;
wherein the sample receiving zone comprises an amount of a third sbp member immobilized within the sample receiving zone and complementary to the analyte, the amount being sufficient to bind a threshold level of the analyte.