Immuno gold lateral flow assay

Inventors

Kirkegaard, Leslie • Ford, Glen

Assignees

Auric Enterprises LLC • Bioassay Works

Abstract

A chromatographic specific binding assay strip device, comprising: a non-permeable platform strip; a permeable membrane testing strip positioned on top of said non-permeable platform strip, with the testing strip comprising at least one capture reagent site containing a capture reagent for at least one specific analyte, a sample receiving pad positioned on top of and at a proximal end of the non-permeable platform strip, with the sample receiving pad having contact with a proximal end of said permeable membrane testing strip, a reservoir pad positioned on top of and at a distal end of said non-permeable membrane testing strip, with the reservoir pad having contact with a proximal end of said permeable membrane test strip; a supporting strip attached to and extending from the proximal end of said non-permeable platform strip; and a conjugate pad positioned on said supporting strip, said conjugate pad comprising a semi-permeable membrane containing a colorant conjugate. The semi-permeable membrane acts as a barrier between the conjugate pad and the sample receiving pad, regulating the flow through the semi-permeable membrane and overall flow of the assay. By dipping the conjugate pad into a sample solution, there will be increased binding between the analyte in the sample and the conjugate (preferably colloidal gold), thereby giving improved results on the lateral flow assay.

Core Innovation

The disclosure relates to a chromatographic specific binding assay strip device comprising a non-permeable platform strip, a permeable membrane testing strip positioned on top of the non-permeable platform strip, and a conjugate pad positioned upstream from the permeable membrane testing strip. The permeable membrane testing strip is shorter at both ends of the non-permeable platform strip and comprises a capture reagent site having a capture reagent specific for an analyte being tested. The conjugate pad comprises a permeable membrane containing a conjugate and is distinct and not in contact with the permeable test strip.

The device further includes a semi-permeable membrane positioned on top of and in contact with the conjugate pad, having a distal end that overlaps onto a proximal end of the permeable membrane strip, and a sample receiving pad positioned on top of a proximal end of the semi-permeable membrane. The disclosure provides embodiments with different placements of the semi-permeable membrane relative to the conjugate pad and/or the sample receiving pad, including an overlapping or tail-folded semi-permeable membrane arrangement and embodiments with more than one semi-permeable membrane.

The disclosed workflow includes an extended semi-permeable membrane/conjugate pad that is dipped into sample to rehydrate and homogenize the conjugate for increased analyte-conjugate complex formation, in the context of an immuno-gold lateral flow (chromatographic specific binding) assay strip device. The disclosed system is associated with improving capillary flow and interaction conditions by regulating nonspecific components and slowing migration so that the assay provides clearer/crisper lines and improved sensitivity.

Claims Coverage

The partial content provides one independent claim (clm-00001). Across this independent claim, the coverage centers on five key inventive features: the non-permeable platform strip, the permeable membrane testing strip with a capture reagent site for an analyte, the upstream conjugate pad with a permeable membrane containing a conjugate distinct and not contacting the test strip, the semi-permeable membrane overlapping onto the permeable membrane strip, and the sample receiving pad positioned on top of the proximal end of the semi-permeable membrane.

The independent claim coverage is directed to a chromatographic specific binding assay strip device that combines an upstream, non-contact conjugate pad with a downstream permeable membrane testing strip carrying an analyte-specific capture reagent site, and uses a semi-permeable membrane whose distal end overlaps onto the testing strip while a sample receiving pad is placed on the proximal end of the semi-permeable membrane.

Stated Advantages

Documented Applications