(h Albumin ELISA, Strip Plate) The Albuwell Hu kit contains all of the components and...
Albuwell M: A murine microalbuminuria ELISA. Intended Use: Albuwell M is an enzyme linked immunosorbent...
The Albuwell O kit contains all of the components and reagents you need to assay...
For the measurement of rat urine albumin. Intended Use: Nephrat is an enzyme linked immunosorbent...
Efficiently assess kidney function through ELISA-based microalbuminuria measurement from human, mouse, sheep, and rat samples.
FOR RESEARCH USE ONLY
Part of our Exocell ELISA portfolio, each microalbuminuria ELISA kit provides robust quantitative detection and monitoring of microalbuminuria, which is defined as concentrations of albumin in the urine that are not detectable by conventional dipstick methods. These assays are highly specific, easy to use, and assist in monitoring the development of incipient nephropathy.
Unlike other ELISA kits which are designed to measure the much higher concentrations of albumin present in plasma or serum, Albuwell and Nephrat II ELISAs are optimized for highly accurate and precise measurement of the much lower concentrations of albumin present in the urine during nephropathy or kidney injury. Included reagents are either ready-to-use or require minimal dilution, which limits the introduction of variability. Figure 1 demonstrates the robustness of the Albuwell M assay during generation of a standard curve, where the average coefficient of variation (CV) is only 4.166% (n = 8).
Albuwell H, M, O, and Nephrat II ELISAs are set up as competitive ELISA assays. The human, mouse, sheep, and rat kits use direct detection for the most streamlined workflows, with the sheep kit implementing indirect detection using rabbit anti-ovine albumin as the primary antibody. Detection is accomplished via conjugated horseradish peroxidase (HRP) and a colorimetric substrate that absorbs at 450 nm.
What’s a competitive ELISA?
As the name suggests, in a competitive ELISA, the amount of analyte in a sample is determined via a competitive reaction where increasing amounts of analyte result in decreased signal. Here’s how it works:
In a competitive ELISA, the wells of the plate are pre-coated with set amounts of purified analyte which remains immobilized in the well. In the absence of sample, addition of the detection antibody results in maximum signal. However, when sample is added, any analyte present will compete with the immobilized analyte for binding to the detection antibody, resulting in decreased antibody remaining the wells after washing and, thus, decreased signal in the presence of analyte.
Why use a competitive ELISA?
Competitive ELISAs deliver highly quantitative results yet are relatively quick to complete as they require little to no sample processing. Because detection is via a competitive reaction, the impact of low affinity, off-target binding is minimized enabling the use of fairly crude samples and rendering the assay less sensitive to sample dilution and sample matrix effects. Competitive ELISAs are also more reproducible, with low variability between duplicates and from assay-to-assay, and they have the flexibility to work with small antigens, antigens with few epitopes, and unpurified or polyclonal antibodies.
What is direct vs. indirect detection?
Direct versus indirect detection refers to how HRP is introduced into the assay. With direct detection, HRP is conjugated directly to the antibody that recognizes the analyte. This is the simpler and quicker of the two methods as only a single antibody is needed. With indirect detection, a primary antibody recognizes the analyte, and then a secondary antibody conjugated to HRP recognizes the primary antibody. The addition of the secondary antibody adds wash steps, increasing the time and labor involved in the assay workflow as well as adding steps where variability can be introduced.