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Human Tumor Necrosis Factor α (TNF-α) ELISA Kit


Species Reactivity

Human (Homo sapiens)

UniProt

P01375

Abbreviation

TNF-α

Alternative Names

TNF; DADB-70P7.1; DIF; TNF-alpha; TNFA; TNFSF2; APC1 protein|TNF superfamily; member 2|TNF; macrophage-derived|TNF; monocyte-derived|cachectin|tumor necrosis factor alpha; TNFSF7

Range

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Sensitivity

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Sample Type

Serum, Plasma, Other biological fluids

Detection Method

Sandwich

Analysis Method

Quantitive

Assay Duration

1-4.5h

Sample Volume

1-200 μL

Detection Wavelengt

450 nm

Cat

AE13959HU

Size

48T 96T

Price

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Availability

3-5 working days

Manual

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Test principle:
This assay employs a two-site sandwich ELISA to quantitate TNF-α in Human serum, plasma. An antibody specific for TNF-α has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any TNF-α present is bound by the immobilized antibody. After removing any unbound substances, a biotin-conjugated antibody specific for TNF-α is added to the wells. After washing, Streptavidin conjugated Horseradish Peroxidase (HRP) is added to the wells. Following a wash to remove any unbound avidin-enzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of TNF-α bound in the initial step. The color development is stopped and the intensity of the color is measured.

Product Overview:
TNFa is synthesized as a 26 kDa, type II transmembrane protein that is 233 amino acids in length. It contains a 30 amino acid (aa) cytoplasmic domain, a 26 aa transmembrane segment, and a 177 aa extracellular region. TNFa is assembled intracellularly to form a transmembrane, non-covalently-linked homotrimeric protein. The 157 aa residue soluble form of TNFa (sTNF-α is released from the C-terminus of the transmembrane protein through the activity of TNFa-converting enzyme (TACE), a membrane-bound disintegrin metalloproteinase. Rat cells known to express TNF-αinclude B cells, colonic columnar epithelial cells, NK and CD3 CD56 hepatic natural T cells, macrophages, monocytes and monocyte-derived dendritic cells, CD4 and CD8 T cells, mast cells, neutrophils, keratinocytes, plasma cells, and adipocytes.

Components:

Reagents

Quantity

Reagents

Quantity

Assay plate (96 Wells)

1

Instruction manual

1

Standard (lyophilized)

2

Sample Diluent

1 x 20 mL

Biotin-Conjugate (concentrate 100 x)

1 x 120 μL

Biotin-Conjugate Diluent

1 x 20 mL

Streptavidin-HRP  (concentrate 100 x)

1 x 120 μL

Streptavidin-HRP Diluent   

1 x 20 mL

Wash Buffer (concentrate 25 x)

1 x 20 mL

Substrate Solution

1 x 12 mL

Stop Solution

1 x 10 mL

Adhesive Films

4

Specificity:
This assay has high sensitivity and excellent specificity for detection of Human TNF-α. No significant cross-reactivity or interference between Human TNF-α and analogues was observed.

Recovery:
Matrices listed below were spiked with certain level of recombinant Human TNF-α and the recovery rates were calculated by comparing the measured value to the expected amount of Human TNF-α in samples.

Sample Type

Number

Recovery range (%)

Average(%)

Serum

10

90-101

96

EDTA plasma

10

89-97

93

Heparin plasma

10

91-99

95

Precision:
Intra-assay Precision (Precision within an assay) 
Three samples of known concentration were tested twenty times on one plate to assess intra-assay precision.
Inter-assay Precision (Precision between assays) 
Three samples of known concentration were tested in forty separate assays to assess inter-assay precision.
CV (%) = SD/meanX100
Intra-Assay: CV<8% 
Inter-Assay: CV<12%

Linearity:
The linearity of the kit was assayed by testing samples spiked with appropriate concentration ofHuman TNF-α and their serial dilutions. The results were demonstrated by the percentage of calculated concentration to the expected.

Sample Type

1:2

1:4

1:8

1:16

Serum

78-89%

81-99%

92-103%

95-105%

EDTA plasma

91-101%

90-98%

93-101%

91-98%

Heparin plasma

92-103%

93-102%

92-99%

91-101%

Stability:
The stability of ELISA kit is determined by the loss rate of activity. The loss rate of this kit is less than 5% within the expiration date under appropriate storage condition. The loss rate was determined by accelerated thermal degradation test. Keep the kit at 37°C for 4 and 7 days, and compare O.D.values of the kit kept at 37°C with that of at recommended temperature. (referring from China Biological Products Standard, which was calculated by the Arrhenius equation. For ELISA kit, 4 days storage at 37°C can be considered as 6 months at 2 - 8°C, which means 7 days at 37°C equaling 12 months at 2 - 8°C).

Sample collection and storage:
Serum: Use a serum separator tube (SST) and allow samples to clot for two hours at room temperature or overnight at 2 - 8°C before centrifugation for 15 minutes at 1000 × g. Remove serum and assay immediately or aliquot and store samples at ≤ -20°C. Avoid repeated freeze-thaw cycles. Plasma: Collect plasma using EDTA, or heparin as an anticoagulant. Centrifuge for 15 minutes at 1000 × g at 2 - 8°C within 30 minutes of collection. Assay immediately or aliquot and store samples at ≤ -20°C. Avoid repeated freeze-thaw cycles. Other biological fluids: Centrifuge samples for 20 minutes at 1000 × g. Remove particulates and assay immediately or store samples in aliquot at -20°C or -80°C. Avoid repeated freeze/thaw cycles.

Kits storage instructions:
Store at 2-8°C. Please refer to Instruction Manual.