Lateral flow assay for detecting multiple proteins of a pathogen
A lateral flow assay device includes a test strip that is configured to receive a sample fluid and detect a presence of antibodies to one or more of a plurality of proteins of the target pathogen. The lateral flow assay device includes a conjugate pad and a membrane. The conjugate pad contains a plurality of the proteins of the target pathogen, each conjugated with a label. If the sample fluid contains antibodies that are specific to the target pathogen through any of the target pathogen's proteins, a binding takes place between those antibodies and the corresponding tagged protein. The membrane may include a plurality of test lines. Each test line may contain the immobilized binding reagent to one antibody class, resulting in the concentration of all the molecules of that antibody class on the test line.
1. A lateral flow assay device, comprising:
a test strip configured to receive a sample fluid and detect a presence of antibodies to a target pathogen, each antibody specific to one of a plurality of proteins of the target pathogen, each antibody belonging to one of a plurality of classes of antibodies, the test strip comprising:
a conjugate pad,
wherein the conjugate pad is configured to receive a quantity of fluid after a start of a test and move the fluid by capillary action, and
wherein the conjugate pad is configured to contain a plurality of classes of antibodies to the target pathogen that are conjugated with a label, and
a membrane fluidly connected to the conjugate pad,
wherein the membrane is configured to move the fluid by capillary action, and
wherein the membrane comprises a test line comprising a plurality of different proteins of the target pathogen immobilized on the test line.
2. The lateral flow assay device of claim 1 , wherein the plurality of different proteins of the target pathogen immobilized on the test line are combined on the test line.
3. The lateral flow assay device of claim 1 , wherein the plurality of different proteins of the target pathogen immobilized on the test line comprises first and second proteins of the target pathogen, wherein the test line comprises first and second halves with a separation between the first and second halves, wherein the first protein of the target pathogen is immobilized on the first half of the test line, and wherein the second protein of the target pathogen is immobilized on the second half of the test line.
4. The lateral flow assay device of claim 1 , wherein the plurality of different proteins of the target pathogen immobilized on the test line comprises more than two proteins of the target pathogen, wherein the test line comprises a plurality of portions with a separation between each two adjacent portions, wherein each portion of the test line comprises an immobilized protein of the plurality of proteins of the target pathogen.
5. The lateral flow assay device of claim 1 , wherein the test line is a first test line, wherein the lateral flow assay device comprises a second test line comprising at least one immobilized protein of the target pathogen.
6. The lateral flow assay device of claim 1 , wherein the test line is a first test line, wherein the lateral flow assay device comprises a plurality of test lines other than the first test line, wherein each of the plurality of test lines comprises at least one immobilized protein of the target pathogen.
7. The lateral flow assay device of claim 1 , wherein the plurality of classes of antibodies conjugated with the label comprises two classes of antibodies conjugated with a label.
8. The lateral flow assay device of claim 1 , wherein the plurality of classes of antibodies conjugated with the label comprises more than two classes of antibodies conjugated with a label.
9. The lateral flow assay device of claim 1 , wherein the target pathogen is severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) virus.
10. The lateral flow assay device of claim 1 , wherein the membrane comprises a control line comprising immobilized antibodies configured to bind to the plurality of classes of antibodies to the target pathogen that are conjugated with the label.
11. The lateral flow assay device of claim 1 , wherein the sample fluid is a blood sample.
12. The lateral flow assay device of claim 11 further comprising a plasma filter configured to receive the blood sample and transfer the blood sample to one of the conjugate pad and a sample pad of the lateral flow assay device.
13. The lateral flow assay device of claim 1 , wherein the plurality of classes of the antibodies comprises at least two of immunoglobulin A (IgA), immunoglobulin D (IgD), immunoglobulin E (IgE), immunoglobulin G (IgG), and immunoglobulin M (IgM).
14. The lateral flow assay device of claim 1 , wherein the label is a detector comprising at least one of metallic sols comprising colloidal gold, dye sols, colored latex particles, and carbon.
15. The lateral flow assay device of claim 1 further comprising a wicking pad configured to maintain a capillary flow from the membrane into the wicking pad.
16. The lateral flow assay device of claim 1 , wherein the target pathogen is one of a bacterium, a virus, a protozoan, a prion, a viroid, and fungus.
17. The lateral flow assay device of claim 1 further comprising a sample pad configured to receive the sample fluid and transfer the sample fluid by capillary action to the conjugate pad.