Comparison on Measuring Human IL-15/IL-15R Complex (see Technical Data Sheet)

Representative Standard Curve in Standard Diluent (see Technical Data Sheet)

PBL's Human IL-15 ELISA Exhibits Greater Sensitivity than Competitive IL-15 Standards (see Technical Data Sheet)

Representative Standard Curves in Various Matrices (see Technical Data Sheet)

Percent Recovery of IL-15 in Various Matrices (see Technical Data Sheet)

Human IL-15 ELISA Normal Human Serum (NHS) Linearity (see Technical Data Sheet)

Linearity in Tissue Culture Media (TCM) (see Technical Data Sheet)

Human IL-15 ELISA Normal Human Serum (NHS) Parallelism (see Technical Data Sheet)

Human IL-15 ELISA Plasma Parallelism (see Technical Data Sheet)

Human IL-15 ELISA Normal Human Serum (NHS) and Plasma Knockout (see Technical Data Sheet)

Human IL-15 ELISA Kit, High Sensitivity (Serum, Plasma, TCM)

1 Citations

Catalog Number: 41702

The Human Interleukin 15 ELISA measures endogenous human IL-15 at or near basal levels with LLOQ of 0.51 pg/ml in serum, plasma, and cell culture media. This ELISA detects both free and bound forms of IL-15 (IL-15/IL-15R complex).

Product Name: VeriKine-HS Human Interleukin 15 ELISA Kit

$655.00

Matrix Compatibility	Serum, Plasma, Tissue Culture Media
Assay Range	0.51 - 32.8 pg/ml
LLOQ	0.51 pg/ml Need more sensitivity? Check out our Sample Testing Services
Assay Length	4 hours
Specificity	Human Interleukin 15
CVs	Inter-Assay: < 10% Intra-Assay: < 10% Spike recovery: 103%

This ELISA measures IL-15 in tissue culture media (TCM), serum and plasma. It measures both IL-15 alone and IL-15/IL-15Rα complexes and quantitates IL-15 in healthy donor matrices. This assay’s standard is the IL-15 receptor heterodimer, but the standard curve is calibrated to the IL-15 portion of the complex since the antibodies used are IL-15 specific.

This kit quantitates free human IL-15 and bound IL-15/IL-15R in serum, plasma and TCM using a sandwich immunoassay. The kit is based on an ELISA with biotinylated-detection antibody and streptavidin-conjugated horseradish peroxidase (HRP). Tetramethyl-benzidine (TMB) is the substrate.

CVs and Spike Recovery	Inter-Assay: < 10% Intra-Assay: < 10% Spike recovery: 103%
Cross-reactivity	No cross-reactivity detected with Human IL-2, IL-4, IL-7, IL-9, IL-21, IFN-α, IFN-β1a, IFN-γ, IFN-ω Cynomolgus IFN-α2 Cynomolgus/Rhesus IFN-α Mouse IL-15, IFN-αA, IFN-β, IFN-γ Rat IL-15, IFN-α1, IFN-α14, IFN-β, IFN-γ Bovine IFN-τ2 Pig IFN-α
Storage	2-8 °C
Expiration Date	One year from the date of manufacture
Shipping Condition	Wet Ice

Materials Provided

Pre-Coated Micro-Titer Stripwell Plate/Sealers
Wash Solution Concentrate
Human Interleukin-15 Standard (410 pg/ml)
Assay Buffer
Dilution Buffer
Antibody Concentrate
HRP Conjugate Concentrate
Concentrate Diluent
HRP Diluent
TMB Substrate Solution
Stop Solution

Additional Materials Required (Not Provided)

Microplate reader capable of reading an OD at a wavelength of 450 nm
Variable volume microtiter pipettes
Adjustable multichannel pipette (50-300 μl)
Reagent reservoirs
Wash bottle or plate washing system
Distilled or deionized water
Serological pipettes (1, 5, 10 or 25 ml)
Disposable pipette tips (polypropylene)
Plate shaker

Representative Standard Curve in Standard Diluent

41702 Typical Standard Curve in Standard Diluent — Human IL-15 standard curves were prepared in Standard Diluent (SD) and assayed in triplicate over 9 runs. The figure below shows dose response and absorbance values. Error bars indicate standard deviation.

Intra-Assay Precision
Sample	1	2	3	4	5	6
n	26	26	26	26	26	26
Mean (pg/ml)	4.17	4.42	4.20	2.81	3.85	3.87
Std. Dev.	0.18	0.09	0.18	0.10	0.13	0.13
CV (%)	4.4	1.9	4.3	3.6	3.3	3.3

Inter-Assay Precision
Sample	1	2	3	4	5	6	7
Mean (pg/ml)	4.52	3.55	4.47	2.87	3.54	12.55	3.68
Std. Dev.	0.24	0.16	0.17	0.16	0.19	0.61	0.13
CV (%)	5.3	4.6	3.7	5.4	5.4	4.8	3.4

Inter-Batch Precision
Sample	1	2	3	4	5	6	7
Lot 1 (pg/ml)	5.26	3.97	5.12	3.24	4.02	13.94	4.18
Lot 2 (pg/ml)	5.16	3.94	5.09	3.20	3.97	13.58	4.26
Lot 3 (pg/ml)	4.80	3.62	4.71	2.85	3.66	12.77	3.86
Mean (pg/ml)	5.07	3.84	4.97	3.10	3.88	13.43	4.10
Std. Dev.	0.24	0.19	0.22	0.21	0.20	0.60	0.21
CV(%)	4.7	5.0	4.5	6.8	5.1	4.5	5.1

Intermediate Precision
Sample	1	2	3	4	5	6	7
n	27	27	27	27	27	27	27
Mean (pg/ml)	5.07	3.84	4.97	3.10	3.88	13.43	4.05
Std. Dev.	0.63	0.49	0.57	0.38	0.45	1.30	0.40
CV (%)	12.5	12.9	11.5	12.4	11.6	9.7	9.9

Spike Recovery

TCM
Disodium-EDTA Plasma
Serum
Spike Sample	1	2	3
Target Conc. (pg/ml)	24.61	6.15	0.82
Mean Recovery	92.8	97.0	94.0
Range (%)	91.5 – 95.1	93.3 – 99.0	93.5 – 94.5
Spike Sample	1	2	3
Target Conc. (pg/ml)	24.61	6.15	0.82
Mean Recovery	98.1	99.9	82.1
Range (%)	78.4 – 104.5	85.1 – 108.1	64.9 – 95.3
Spike Sample	1	2	3
Target Conc. (pg/ml)	24.61	6.15	0.82
Mean Recovery	99.2	94.7	75.6
Range (%)	99.2	94.7	75.6

Representative Standard Curves in Various Matrices

Percent Recovery of IL-15 in Various Matrices

MDD/LOQ
Assay	1	2	3
n	80	80	80
Mean Blank (A₄₅₀)	0.055	0.052	0.057
Std. Dev.	0.004	0.007	0.008
MDD (A₄₅₀)	0.067	0.072	0.079
MDD (pg/ml)	0.104	0.173	0.175
LOQ (Abs₄₅₀)	0.096	0.121	0.132
LOQ (pg/ml)	0.341	0.571	0.575

Linearity in Pooled Healthy Donor Serum (HDS)

Linearity in Tissue Culture Media (TCM)

Parallelism in Individual Healthy Donor Sera (HDS)

Parallelism in Healthy Donor Plasma (HDP)

IL-15 Knockout under Control (Blue) and Specific (Beige) Conditions

41702 Knockout — Samples treated with PBL’s IL-15 specific capture antibody (beige) displayed knockdown of the observed sample concentration when compared to untreated control samples (blue). Samples treated with the specific IL-15 capture antibody recorded IL-15 levels at or below the assay LOQ.

Sample	[IL-15] pg/ml Control	[IL-15] pg/ml Specific	[IL-15] pg/ml Isotype
IL-15 Concentrations under Knockout Conditions in HDS and HDP Samples
1	13.12	0.59	6.99
2	4.92	<LOQ	4.4
3	6.38	<LOQ	3.87
4	4.61	<LOQ	4.66
5	4.38	<LOQ	4.55
6	4.61	<LOQ	4.66
7	3.98	<LOQ	3.51
8	3.27	<LOQ	2.95
9	2.52	<LOQ	2.46

Representative Standard Curves on PBL’s IL-15 ELISA (41702) and Competitors

PBL’s and three competitor’s standards were assayed on their respective ELISAs. Dose response curves and absorbance values of all IL-15 standards are shown below. PBL’s standard exhibited greater sensitivity than competitive IL-15 standards; PBL’s standard curve demonstrated an improvement of 1 – 2 log units.

Comparison of PBL’s HEK Standard on Commercial ELISAs

Sample Type	Quantifiable Mean (pg/ml)	Range (pg/ml)	% above LOQ	% below LOQ	%CV
Healthy Donor Readability Comparison
PBL's ELISA
Competitor A's ELISA
Competitor B's ELISA
Competitor C's ELISA
Serum	4.21	2.64– 13.75	100 (30/30)	0 (0/30)	3.0
EDTA Plasma	3.01	1.75– 4.17	100 (17/17)	0 (0/17)	2.4
Citrate Plasma	2.42	1.41– 3.99	100 (13/13)	0 (0/13)	3.1
Heparin Plasma	2.63	1.62– 3.87	100 (13/13)	0 (0/13)	2.9
Serum	91.51	17.84– 244.51	30 (9/30)	70 (21/30)	30.1
EDTA Plasma	35.13	8.89– 126.25	47.1 (8/17)	52.9 (9/17)	10.7
Citrate Plasma	22.00	10.56– 38.40	46 (6/13)	54 (7/13)	14.7
Heparin Plasma	58.48	40.31-76.66	20 (2/10)	80 (8/10)	5.0
Serum	5.78	4.13– 8.11	10 (3/30)	90 (27/30)	6.1
EDTA Plasma	4.74	N/A	5.9 (1/17)	94.1 (16/17)	N/A
Citrate Plasma	N/A	N/A	0 (0/13)	100 (13/13)	N/A
Heparin Plasma	N/A	N/A	0 (0/10)	100 (10/10)	N/A
Serum	N/A	N/A	0 (0/30)	100 (30/30)	N/A
EDTA Plasma	N/A	N/A	0 (0/18)	100 (18/18)	N/A
Citrate Plasma	N/A	N/A	0 (0/12)	100 (12/12)	N/A
Heparin Plasma	N/A	N/A	100 (0/10)	0 (10/10)	N/A

Background

Interleukin-15 (IL-15) is a member of the IL-2 family of cytokines which also includes IL-4, -7, -9 and -21^1,2,3. It has similar and unique functions compared to IL-2. Signaling by IL-15 can be through the cytokine alone, in complex with soluble IL-15RAlpha and transpresented bound to IL15RAlpha. It is produced largely by monocytic cells but also by dendritic cells, keratinocytes, fibroblasts, myocytes, and nerve cells. It seems to enhance the expansion of CD8 memory cells, NK and NK-T cells⁴. IL-15 plays a role in tumor biology and autoimmune diseases including psoriasis, rheumatoid arthritis, inflammatory bowel disease, celiac disease, alopecia areata, and systemic lupus erythematosus^5,6.

1 Citation:

Kumar, A. et al., (2023), "Intrinsic suppression of type I interferon production underlies the therapeutic efficacy of IL-15-producing natural killer cells in B-cell acute lymphoblastic leukemia", J. Immunother. Cancer, 11(5):e006649, PMID: 37217248, DOI: 10.1136/jitc-2022-006649 (link)

Background Literature:

Liao W, Lin JX, Leonard WJ. IL-2 family cytokines: new insights into the complex roles of IL-2 as a broad regulator of T helper cell differentiation. Curr Opin Immunol. 2011;23(5):598-604. (link)
Grabstein KH, et al. Cloning of a T cell growth factor that interacts with the beta chain of the interleukin-2 receptor. Science. 1994 May;264(5161):965-8. (link)
Burton, JD, et al. A lymphokine, provisionally designated interleukin T and produced by a human adult T-cell leukemia line, stimulates T-cell proliferation and the induction of lymphokine-activated killer cells. PNAS. 1994;91:4935-4939. (link)
Ring, AM, et al. Mechanistic and structural insight into the functional dichotomy between IL-2 and IL-15. Nat Immunol. 2012;13(12):1187-95. (link)
Waldmann, TA. The biology of IL-15: implications for cancer therapy and the treatment of autoimmune disorders. J Investig Dermatol Symp Proc. 2013 Dec;16(1):S28-30. (link)
Clark DN, et al. Cytokine inhibition as a strategy for treating systemic lupus erythematosus. Clin Immunol. 2013;148(3):335-43. (link)

Human IL-15 ELISA Kit, High Sensitivity (Serum, Plasma, TCM)