For research use only. Not for use in diagnostic procedures.

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Country︱Company: China︱Beijing Solarbio Science & Technology Co., Ltd

Address: NO.8, Liandong U Valley, Tongzhou District, Beijing, P.R.China.

TABLE OF CONTENTS SECTION

BACKGROUND

Interleukin-2 (IL-2) is an interleukin, a type of cytokine signaling molecule in the immune system. It is a protein that regulates the activities of white blood cells (leukocytes, often lymphocytes) that are responsible for immunity. IL-2 is part of the body's natural response to microbial infection, and in discriminating between foreign ("non-self") and "self". IL-2 mediates its effects by binding to IL-2 receptors, which are expressed by lymphocytes. While the causes of itchiness are poorly understood, some evidence indicates that IL-2 is involved in itchy psoriasis.

PRECAUTIONS

The Stop Solution suggested for use with this kit is an acid solution. Wear protective gloves, clothing, eye, and face protection. Wash hands thoroughly after handling.

KIT COMPONENTS& STORAGE CONDITIONS

**Provided this is within the expiration date of the kit.

OTHER SUPPLIES REQUIRED BUT NOT SUPPLIED

• Microplate reader capable of measuring absorbance at 450 nm.
• Pipettes and pipette tips.
• Deionized or distilled water.
• Squirt bottle, manifold dispenser, or automated microplate washer.
• 500 mL graduated cylinder.
• Human IL-2 controls (optional; available from Solarbio).

SPECIMEN COLLECTION & STORAGE

Cell Culture Supernates - Centrifuge cell culture media at 1000×g to remove debris. Assay immediay or aliquot and store samples at ≤ -20°C. Avoid repeated freeze-thaw cycles.

Serum - Use a serum separator tube (SST) and allow samples to clot for 2 hours at room temperature or overnight at 2-8℃. Centrifuge at approximay for 15 minutes at 1000×g. Assay immediay or aliquot and store samples at ≤ -20°C. Avoid repeated freeze-thaw cycles.

Plasma - Collect plasma using EDTA, heparin, or citrate as an anticoagulant. Centrifuge for 15 minutes at 1000×g within 30 minutes of collection. Assay immediay or aliquot and store samples at ≤ -20°C. Avoid repeated freeze-thaw cycles.

Note: The normal human serum or plasma samples are suggested to make a 1:2 dilution.

REAGENTS PREPARATION

• Temperature returning - Bring all kit components and specimen to room temperature (20-25℃) before use.
• Wash Buffer - Dilute 30mL of Wash Buffer Concentrate with 570mL of deionized or distilled water to prepare 600mL of Wash Buffer. If crystals have formed in the concentrate Wash Buffer, warm to room temperature and mix gently until the crystals have compley dissolved.
• Standard\Specimen - Reconstitute the Standard with 1.0mL of deionized or distilled water. This reconstitution produces a stock solution of 1000pg/mL. Allow the standard to sit for a minimum of 15 minutes with gentle agitation prior to making dilutions. Pipette 500mL of Standard/Specimen Diluent into 500pg/ml tube and the remaining tubes. Use the stock solution of 1000pg/mL to produce a 2-fold dilution series (below). Mix each tube thoroughly and change pipette tips between each transfer. The 500pg/mL standard serves as the high standard. The Standard/specimen Diluent serves as the zero standard (0pg/mL).

*If you do not run out of re-melting standard, store it at -20℃. Diluted standard shall not be reused.

• Working solution of Biotin-Conjugate anti-human IL-2 antibody: Make a 1:100 dilution of the concentrated Biotin-Conjugate solution with the Biotin-Conjugate antibody Diluent in a clean plastic tube.

*The working solution should be used within one day after dilution.

• Working solution of Streptavidin-HRP: Make a 1:100 dilution of the concentrated Streptavidin-HRP solution with the Streptavidin-HRP Diluent in a clean plastic tube. 

*The working solution should be used within one day after dilution.

Preparation of IL-2 standard dilutions

ASSAY PROCEDURE

Typical data using the IL-2 ELISA

Representative standard curve for IL-2 ELISA.

Performance Characteristics

SENSITIVITY: The minimum detectable dose was 4pg/mL.

SPECIFICITY: This assay recognizes both natural and recombinant human IL-2. The factors listed below were prepared at 100ng/ml in Standard /sample Diluent and assayed for cross-reactivity and no significant cross-reactivity or interference was observed.

 Factors assayed for cross-reactivity

REPEATABILITY: The coefficient of variation of both intra-assay and inter-assay were less than 10%.

RECOVERY：The recovery of IL-2 spiked to three different levels in four samples throughout the range of the assay in various matrices was evaluated.

 Recovery of IL-2 in two matrices  

LINEARITY:To assess the linearity of the assay, three samples were spiked with high concentrations of IL-2 in various matrices and diluted with the appropriate Sample Diluent to produce samples with values within the dynamic range of the assay.

 The linearity of the assay