The Erenna® IL-2 Immunoassay uses a quantitative fluorescent sandwich immunoassay technique to measure IL-2 in human serum and plasma samples. A capture antibody specific for human IL-2 has been pre-coated onto paramagnetic microparticles (MPs). The user pipettes MPs, standards, and samples into uncoated microplate wells. During incubation, the IL-2 present in the sample binds to the capture antibody on the coated MPs. Unbound molecules are washed away during the subsequent buffer exchange and wash steps. Fluor-labeled detection antibody is added to each well and incubated. This detection antibody recognizes and binds to IL-2 that has been captured onto the MPs. During the following wash step the MPs are transferred to a clean plate. Elution buffer is then added and incubated. The elution buffer dissociates the bound protein sandwich from the MP surface, releasing the labeled antibodies. These antibodies are separated during transfer to a final microplate. The plate is loaded into the Erenna® System where the labeled molecules are detected and counted. The number of fluor-labeled detection antibodies counted is directly proportional to the amount of IL-2 present in the sample when captured. The amount of IL-2 in unknown samples is interpolated from a standard curve.
TABLE 1. Analytical sensitivity of the Erenna® IL-2 Immunoassay Kit1
Lower Limit of Detection
Lower Limit of Quantification2
Upper Limit of Quantification
Low-end CV% Range
3 – 10%
Low-end CV% Average
Recommended Sample Volume
Minimum Sample Volume Required3
1 See product insert for updated values 2 LLoQ = 20% CV and ± 20% recovery 3 based upon median [IL-2] in a healthy reference
FIGURE 1. [IL-2] in EDTA plasma from 10 healthy donors, with median and interquartile range. The Erenna® IL-2 Immunoassay Evaluation Reagent Kit reliably quantifies IL-2 in healthy subjects, who have a median [IL-2] of 0.21 pg/mL that is well above the detection limit of 0.01 pg/mL.
FIGURE 2. Erenna® IL-2 Immunoassay Evaluation Reagent Kit low-end standard curve signal (left) and curve fit (right).
Representative data shown for demonstration purposes only. Individual results may vary depending upon samples tested and protocol used.
Biology and Disease
Interleukin-2 (IL-2) is a naturally produced cytokine whose key function is to activate the immune system during an infectious attack. Foreign antigens trigger IL-2 secretion. When IL-2 binds to its receptor IL-2R, the complex stimulates immune cell proliferation and differentiation, including cytotoxic T-cells, natural killer cells, lymphocytes, monocytes and macrophages. Interestingly, research suggests that impaired IL-2 activity has been linked to the development of autoimmunity rather than immunodeficiency. Autoimmune system hyperactivity may cause chronic inflammatory disorders, lymphadenopathy, hepatomegaly, and splenomegaly. Recent studies also suggest an important role for IL-2 in the regulation of innate immunity.
Produced by T-cells in response to antigenic or mitogenic stimulation, this protein is required for T-cell proliferation and other activities crucial to regulation of the immune response. Can stimulate B-cells, monocytes, lymphokine-activated killer cells, natural killer cells, and glioma cells.
T cell differentiation, anti-apoptosis, cell adhesion, cell-cell signaling, immune response, natural killer cell activation, negative regulation of B cell apoptosis, positive regulation of B cell proliferation, positive regulation of activated T cell proliferation, positive regulation of cell growth