Detection systems utilizing supported lipid bilayers
The invention relates to lipid bilayer coated beads and methods of using those beads in immunoassays, in analytical assay and the like.
1. An assay for detecting an antigen, which comprises:
(a) providing a lipid bilayer coated bead that displays a binding agent, wherein a detectable label is encapsulated by the lipid bilayer;
(b) linking a ligand to a selected antigen in a test sample to generate a test antigen-ligand conjugate, wherein the ligand will bind to the binding agent displayed by the bead;
(c) contacting the test antigen-ligand conjugate with an antibody to from an antibody-antigen-ligand complex that, when exposed to a substrate, produces a product that disrupts the lipid bilayer due to catalytic activity of the antibody in the antibody-antigen-ligand complex;
(d) contacting the bead with the antibody-antigen-ligand complex to form an antibody-antigen-ligand-bead complex;
(e) removing unbound antibody;
(f) exposing the remaining antibody to the substrate; and
(f) observing whether a signal from the detectable label is altered.
2. The assay of claim 1 , wherein the product is antibody-generated ozone or hydrogen peroxide.
3. The assay of claim 2 , wherein the substrate is a singlet oxygen sensitizer.
4. The assay of claim 2 , further comprising irradiating the antibody-antigen-ligand-bead complex before observing whether a signal from the detectable label is altered.
5. The assay of claim 1 , wherein the binding agent is biotin, streptavidin or an IgG receptor.
6. The assay of claim 1 , further comprising adding a competitive antigen to the test sample prior to linking the ligand to the selected antigen, wherein the competitive antigen is linked to an agent that inhibits antibody-generated ozone or hydrogen peroxide.
7. The assay of claim 6 , wherein the agent that inhibits antibody-generated ozone or hydrogen peroxide is catalase.
8. The assay of claim 1 , wherein the selected antigen is a viral antigen, a cancer antigen, a bacterial antigen, a fungal antigen, an autoimmune antigen or a combination thereof.
9. The assay of claim 1 wherein the catalytic activity of the antibody enables disruption of the lipid bilayer via the product.