Human IL-2 Quantikine QuicKit ELISA

Name: Human IL-2 Quantikine QuicKit ELISA
Brand: R&D Systems
SKU: QK202
Rating: 5 (1 reviews)

Catalog #: QK202 1 Review Datasheet / COA / SDS

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QK202

Control Products Available

QC261: Human IL-2 Quantikine QuicKit Control Group 261

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Summary Sample Values Precision Recovery Linearity Data Examples Product Datasheets Preparation and Storage Background Related Research Areas

Human IL-2 Quantikine QuicKit ELISA Summary

Assay Length

80 minutes

Sample Type & Volume Required Per Well

Cell Culture Supernates (50 uL), Serum (50 uL), EDTA Plasma (50 uL), Heparin Plasma (50 uL)

Sensitivity

2.01 pg/mL

Assay Range

31.3 - 2,000 pg/mL (Cell Culture Supernates, Serum, EDTA Plasma, Heparin Plasma)

Specificity

Natural and recombinant human IL-2.

Cross-reactivity

< 0.5% cross-reactivity observed with available related molecules.< 50% cross-species reactivity observed with species tested.

Interference

No significant interference observed with available related molecules.

Sample Values

Serum/Plasma - Ten serum and plasma samples from apparently healthy volunteers were evaluated for the presence of human IL-2 in this assay. All samlpes measured less than the lowest standard, 31.3 pg/mL. No medical histories were available for the donors used in this study.

Cell Culture Supernates - Human peripheral blood mononuclear (PBMCs) cells were cultured in RPMI supplemented with 10% fetal bovine serum, 2 mM L-glutamine, 100 U/mL penicillin, and 100 μg/mL streptomycin sulfate. The cells were cultured unstimulated or stimulated with 10 μg/mL PHA for 24 hours. Aliquots of the cell culture supernates were removed, assayed for levels of human IL-2, and were undetectable or measured 390 pg/mL, respectively.

CD4+ T cells were isolated from PBMCs and cultured in RPMI supplemented with 10% fetal bovine serum, 2 mM L-glutamine, 100 U/mL penicillin, and 100 μg/mL streptomycin sulfate. Cells were stimulated with plate-bound Mouse Anti-human CD3 (Catalog # MAB100) and soluble Mouse anti-human CD28 (Catalog # MAB342) for 5 days, followed by 10 ng/mL PMA and 500 ng/mL Calcium Ionomycin for 24 hours. An aliquot of the cell culture supernate was removed, assayed for human IL-2, and measured 84,350 pg/mL.

Product Summary

The Quantikine^® QuicKit™ Human IL-2 Immunoassay is a one step, 80-minute solid phase ELISA designed to measure human IL-2 levels in cell culture supernates, serum, and plasma. It contains E. coli-expressed recombinant human IL-2 and antibodies raised against the recombinant protein. Results obtained for naturally occurring human IL-2 showed linear curves that were parallel to the standard curves obtained using the recombinant QuicKit™ standards. These results indicate that this kit can be used to determine relative mass values for natural IL-2.

Precision

Intra-Assay Precision (Precision within an assay) Two samples of known concentration were tested twenty times on one plate to assess intra-assay precision

Inter-Assay Precision (Precision between assays) Two samples of known concentration were tested in ten separate assays to assess inter-assay precision. Assays were performed by at least three technicians

Cell Culture Supernates, Serum, Plasma, EDTA Plasma, Heparin Plasma

	Intra-Assay Precision		Inter-Assay Precision
Sample	1	2	1	2
n	20	20	10	10
Mean (pg/mL)	217	1231	213	1331
Standard Deviation	5.7	33.1	17.1	67.7
CV%	2.6	2.7	8	5.1

Recovery

The recovery of human IL-2 spiked to three levels in samples throughout the range of the assay was evaluated.

Sample Type	Average % Recovery	Range %
Cell Culture Media (n=4)	112	103-119
EDTA Plasma (n=2)	85	72-96
Heparin Plasma (n=2)	85	74-93
Serum (n=2)	91	73-105

Linearity

To assess the linearity of the assay, samples were spiked with high concentrations of human IL-2 in various matrices and diluted with 1X Kit Diluent to produce samples with values within the dynamic range of the assay.

Scientific Data

N/A

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Human IL-2 ELISA Standard Curve

ELISA

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Human IL-2 QuicKit Spiked Recovery Competitor Comparison IL-2 is spiked at three known concentrations throughout the range of the assay and run to measure response of the spiked sample matrix. Serum recovery is 103% compared to 113% for the top competitor. EDTA Plasma recovery is 107% compared to 111% for the top competitor. Heparin Plasma recovery is 100% compared to 102% for the top competitor. In spike and recovery experiments, natural samples are spiked with the recombinant target analyte of interest to identify interference caused by sample matrices.

Product Datasheets

Product Datasheet

COA

SDS

Preparation and Storage

Shipping

The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.

Storage

Store the unopened product at 2 - 8 °C. Do not use past expiration date.

Background: IL-2

Interleukin 2 (IL-2), also known as T cell growth factor (TCGF), is a 15-18 kDa variably glycosylated alpha -helical polypeptide that is a member of the Common gamma Chain ( gamma c) cytokine family (1-4). It exists as a monomer and has a notably short half-life (< 30 minutes) (1). Human IL-2 is synthesized as a 153 amino acid (aa) precursor that contains a 20 aa signal sequence plus a 133 aa mature region (5, 6). The mature region is alpha -helical in nature, and contains one utilized O-linked glycosylation site at Thr3 plus three cysteines, two of which form an intrachain disulfide bond that is essential for activity (7). Mature human IL-2 shares 73%, 66%, 78% and 97% aa identity with canine, rat, feline and rhesus monkey IL-2, respectively. Although human IL-2 shares only approximately 60% aa identity with the highly polymorphic mouse IL-2, human IL-2 is known to be active on mouse IL-2 responsive cells. Cells reported to secrete IL-2 include gamma δ T cells (8), activated conventional CD4+ and CD8+ T cells (1, 9), neurons (10, 11), microglia (12), and hematopoietic stem cells (13).

The receptor for IL-2 (IL-2 R) is composed of three subunits, the 55 kDa CD25/IL-2 R alpha chain, the 70 kDa IL-2 R beta chain, and the 65 kDa Common gamma Chain (1, 3). IL-2 first binds to CD25, the binary complex then recruits IL-2 R beta and gamma c to form the quaternary signaling complex (1, 14). In addition to IL-2, IL-2 R beta is used by IL-15 in its quaternary signaling complex. gamma c also serves as a signaling receptor for IL-4, -7, -9, -15, and -21 (1, 3).

In vitro studies have shown an important role for IL-2 in T cell activation and expansion. In vivo, IL-2 is critical for the development, maintenance and function of regulatory T cells (Treg) which provide protection against autoimmune disease. On the other hand, IL-2 can also promote autoimmune inflammation in target organs through its roles in regulating the expression of T cell trafficking genes, and production of Th2 cytokines. Within the CD8+ T cell subset, IL-2 is essential for optimal primary responses and differentiation into terminal effector cells. IL-2 also promotes the development of activated CD8+ T cells into memory cells. (1).

Long Name:

Interleukin 2

Entrez Gene IDs:

3558 (Human); 16183 (Mouse); 116562 (Rat); 396868 (Porcine); 280822 (Bovine); 403989 (Canine); 100034204 (Equine); 751114 (Feline); 100302458 (Rabbit)

Alternate Names:

Aldesleukin; IL2; IL-2; IL-2lymphokine; interleukin 2; interleukin-2; involved in regulation of T-cell clonal expansion; Proleukin; T cell growth factor; T-cell growth factor; TCGF

Related Research Areas

Assay Procedure

These assays utilize an anti-tag coated microplate. Standards, samples, and controls are added to plate, followed by subsequent addition of an antibody cocktail. Following a 1 hour incubation, plates are washed and substrate is added and incubated for 20 minutes. Stop solution is then added and plates are read using a standard microplate reader.

QuicKit ELISA assay procedure