Human IL31 Assay Kit

IL31 is preferentially produced by TH2 cells, and acts on activated monocytes and unstimulated epithelial cells.
It could be involved in skin inflammation and especially pruritus (itching).
Cisbio's Human IL31 kit is a homogeneous, add and read assay to measure IL31 secretion in supernatant. It offers a fast, efficient alternative to ELISA.

Sample size 16 µL
Final assay volume 20 µL
Kit components Lyophilized standard, frozen detection antibodies, buffers & protocol.
LOD &OQ (in Diluent) 18 pg/mL & 87 pg/mL
Range 87 – 20,000 pg/mL
Time to result Overnight at RT
Species Human only
Download Insider tips for PBMC isolation Technical Note
Download cytokine release from fresh blood samples application notes

Assay principle

The assay protocol, using a Cisbio 96-well low volume or a 384-well small volume white plate (20 µL final), is described below. Cell supernatant, sample or standard are dispensed directly into the assay plate for the detection by HTRF® reagents. The antibodies labeled with the HTRF donor and acceptor are pre-mixed and added in a single dispensing step, to further streamline the assay procedure. The assay can be run in 96 to 1536-well plates by simply resizing each addition volume proportionally.

The 4 Parameter Logistic (4PL) curve is commonly recommended for fitting an ELISA standard curve. This regression enables the accurate measurement of an unknown sample across a wider range of concentrations than linear analysis, making it ideally suited to the analysis of biological systems like cytokine releases.


Cytokines assay principle add


Cytokines assay principle read

(1) Assay data analysis:

  • "Guidelines for data reduction" button will show you how dealing with HTRF data processing and 4PL 1/y2 fitting.
  • "MyAssays" button will direct you to a free online software able to run hIL31 analysis.


How to use HTRF cytokine assays

How to measure multiple cytokines from 1 sample

Analytical performance


Intra-assay (n=24)

Sample Mean [IL31] (pg/mL) CV
1 199 7%
2 9888 6%
3 20883 5%
  Mean CV 6%

Each of the 3 samples was measured 24 times, and % CV was calculated for each sample.

Inter-assay (n=4)

Sample [IL31] (pg/mL) Mean (delta R) CV
1 388 487 19%
2 1878 1674 11%
3 9091 4007 4%
    Mean CV 11%

Each of the samples was measured in 4 different experiments, and % CV was calculated for each sample.

Part#, inserts & MSDS

Ordering Info

DescriptionCat. noProduct insertMSDS
Human IL31 kit - 500 tests62HIL31PEG
Human IL31 kit - 10,000 tests62HIL31PEH

Companion products

DescriptionCat. noProduct insertMSDS
Human IL31 kit - 3 Standards62HIL31CD3
Human IL31 kit - Standard62HIL31CDA