Device For Detection Of Vitamin D Metabolites

What is this patent about?

’524 is related to the field of in-vitro diagnostics , specifically lateral flow assays for detecting and quantifying vitamin D levels in biological samples. Vitamin D deficiency is a widespread health concern, and accurate, rapid testing is needed. Existing methods like LC-MS/MS are accurate but time-consuming and require specialized laboratories. This invention aims to provide a simpler, faster, and more accessible method for determining vitamin D status.

The underlying idea behind ’524 is to use a sandwich immunoassay on a lateral flow strip to detect vitamin D. A vitamin D binding agent (antibody) on a conjugate pad binds to vitamin D in the sample. This complex then flows to a detection zone where a second antibody, specific to the complex formed between the vitamin D and the first antibody, is immobilized. The accumulation of the complex at the detection zone indicates the presence and quantity of vitamin D.

The claims of ’524 focus on a test device comprising a housing containing a sample application pad, a conjugate pad with a vitamin D binding agent, and a detection zone. The key feature is the detection zone, which has a region with an immobilized detection antibody that specifically binds to an epitope formed only when the vitamin D binding agent is complexed with vitamin D. The detection antibody is further defined by specific amino acid sequences for its light and heavy chains.

In practice, a biological sample (e.g., blood) is applied to the sample pad and migrates to the conjugate pad, where vitamin D binds to the vitamin D binding agent. This complex then flows along the strip to the detection zone. If vitamin D is present, the complex will be captured by the immobilized detection antibody, leading to a visible signal (e.g., from gold nanoparticles attached to the vitamin D binding agent). The intensity of the signal correlates with the vitamin D concentration in the sample.

This approach differs from prior methods by using a complex-specific antibody as the detection agent. Instead of directly capturing vitamin D or the vitamin D binding agent, the detection antibody only binds to the unique structure formed when they are combined. This potentially increases the assay's specificity and reduces background noise, leading to more accurate and reliable results. The lateral flow format also provides a rapid and user-friendly testing platform suitable for point-of-care applications.