










Scientific Data
Assay Procedure
ACTIVATION REAGENT PREPARATION
To activate latent TGF-ß1 to the immunoreactive form, prepare the following solutions for acid activation and neutralization. The solutions may be stored in polypropylene bottles at room temperature for up to one month.
Caution: Wear protective clothing and safety glasses during preparation or use of these reagents. Refer to the appropriate MSDS before use.
1 N HCl (100 mL) - To 91.67 mL of deionized water, slowly add 8.33 mL of 12 N HCl. Mix well.
1.2 N NaOH/0.5 M HEPES (100 mL) - To 75 mL of deionized water, slowly add 12 mL of 10 N NaOH. Mix well. Add 11.9 g of HEPES. Mix well. Bring final volume to 100 mL with deionized water.
TGF-β1 SAMPLE ACTIVATION
To activate latent TGF-β1 to immunoreactive TGF-β1, follow the activation procedure outlined below. Assay samples after neutralization (pH 7.2-7.6). Use polypropylene test tubes.
Note: Do not activate the kit standards. The kit standards contain active recombinant TGF-β1.
Cell Culture Supernates | Serum/Plasma |
---|---|
To 100 μL of cell culture supernate, add 20 μL of 1 N HCI. | To 40 μL of serum/plasma, add 10 μL of 1 N HCI. |
Mix well. | Mix well. |
Incubate 10 minutes at room temperature. | Incubate 10 minutes at room temperature. |
Neutralize the acidified sample by adding 20 μL of 1.2 N NaOH/0.5 M HEPES. | Neutralize the acidified sample by adding 10 μL of 1.2 N NaOH/0.5 M HEPES. |
Mix well. | Mix well. |
Assay immediately. | Prior to the assay, dilute the activated sample 60-fold with Reagent Diluent.* |
The concentration read off the standard curve must be multiplied by the dilution factor, 1.4. | The concentration read off the standard curve must be multiplied by the appropriate dilution factor, 90. |
*A suggested 60-fold dilution is 10 μL of activated sample + 590 μL of Reagent Diluent.
GENERAL ELISA PROTOCOL
Plate Preparation
- Dilute the Capture Antibody (to the working concentration stated in the product datasheet ) in PBS without carrier protein. Immediately coat a 96-well microplate with 100 µL per well of the diluted Capture Antibody. Seal the plate and incubate overnight at room temperature.
- Aspirate each well and wash with Wash Buffer, repeating the process two times for a total of three washes. Wash by filling each well with Wash Buffer (400 µL) using a squirt bottle, manifold dispenser, or autowasher. Complete removal of liquid at each step is essential for good performance. After the last wash, remove any remaining Wash Buffer by aspirating or by inverting the plate and blotting it against clean paper towels.
- Block each well of the microplate as recommended in the product datasheet. Incubate at room temperature for a minimum of 1 hour.
Note: The recommended Reagent Diluent typically contains 1% BSA. Some DuoSet Development Kits require alternative blocking agents, or for plates to be blocked overnight with a higher percentage of BSA, please see the product datasheet for details.
- Repeat the aspiration/wash as in step 2. The plates are now ready for sample addition.
PRECAUTION
The Stop Solution suggested for use with this kit is an acid solution. Wear eye, hand, face and clothing protection when using this material.
Assay Procedure
- Add 100 µL of sample or standards in Reagent Diluent, or an appropriate diluent, per well. Cover with an adhesive strip and incubate 2 hours at room temperature.
- Repeat the aspiration/wash as in step 2 of Plate Preparation.
- Add 100 µL of the Detection Antibody, diluted in Reagent Diluent (as recommended in the product datasheet), to each well. Cover with a new adhesive strip and incubate 2 hours at room temperature.
- Repeat the aspiration/wash as in step 2 of Plate Preparation.
- Add 100 µL of the working dilution of Streptavidin-HRP to each well. Cover the plate and incubate for 20 minutes at room temperature. Avoid placing the plate in direct light.
- Repeat the aspiration/wash as in step 2.
- Add 100 µL of Substrate Solution to each well. Incubate for 20 minutes at room temperature. Avoid placing the plate in direct light.
- Add 50 µL of Stop Solution to each well. Gently tap the plate to ensure thorough mixing.
- Determine the optical density of each well immediately, using a microplate reader set to 450 nm. If wavelength correction is available, set to 540 nm or 570 nm. If wavelength correction is not available, subtract readings at 540 nm or 570 nm from the readings at 450 nm. This subtraction will correct for optical imperfections in the plate. Readings made directly at 450 nm without correction may be higher and less accurate.
Mouse TGF-beta 1 DuoSet ELISA Summary
* Provided that the recommended microplates, buffers, diluents, substrates and solutions are used, and the assay is run as summarized in the Assay Procedure provided.
This DuoSet ELISA Development kit contains the basic components required for the development of sandwich ELISAs to measure natural and recombinant TGF-ß1. The Reagent Diluent recommended may be suitable for most cell culture supernate, serum, and plasma samples. The Reagent Diluent selected for use can alter the performance of an immunoassay. Reagent Diluent optimization for samples with complex matrices such as serum and plasma, may improve their performance in this assay.

Background: TGF-beta 1
Transforming Growth Factor Beta 1, 2, and 3 (TGF-beta 1, TGF-beta 2, and TGF-beta 3) are highly pleiotropic cytokines that virtually all cell types secrete. TGF-beta molecules are proposed to act as cellular switches that regulate processes such as immune function, proliferation, and epithelial-mesenchymal transition. Targeted deletions of these genes in mice show that each TGF-beta isoform has some non-redundant functions: TGF-beta 1 is involved in hematopoiesis and endothelial differentiation; TGF-beta 2 affects development of cardiac, lung, craniofacial, limb, eye, ear, and urogenital systems; and TGF-beta 3 influences palatogenesis and pulmonary development. The full range of in vitro biological activities of TGF-beta 5 has not yet been explored. However, TGF-beta 1, TGF-beta 2, TGF-beta 3, and TGF-beta 5 have been found to be largely interchangeable in an inhibitory bioassay, and it is anticipated that TGF-beta 5 will show a spectrum of activities similar to the other TGF-beta family members. To date, the production of TGF-beta 5 has only been demonstrated in Xenopus.
TGF-beta ligands are initially synthesized as precursor proteins that undergo proteolytic cleavage. The mature segments form active ligand dimers via a disulfide-rich core consisting of the characteristic 'cysteine knot'. TGF-beta signaling begins with binding to a complex of the accessory receptor betaglycan (also known as TGF-beta RIII) and a type II serine/threonine kinase receptor termed TGF-beta RII. This receptor then phosphorylates and activates a type I serine/threonine kinase receptor, either ALK-1 or TGF-beta RI (also called ALK-5). The activated type I receptor phosphorylates and activates Smad proteins that regulate transcription. Use of other signaling pathways that are Smad-independent allows for distinct actions observed in response to TGF-beta in different contexts.
