Human TGF-β ELISA Kit

**Human TGF-β ELISA Kit – For the quantitative in vitro determination of Human transforming growth factor β concentrations in serum, plasma, cerebrospinal fluid, tissue homogenate, and other body fluids. Intended for laboratory research use only. NOT FOR USE IN DIAGNOSTIC PROCEDURES.** This ELISA kit is designed for the accurate measurement of TGF-β levels in various biological samples. The principle of the assay relies on a competitive immunoassay format. The color change from blue to yellow is induced by the Stop Solution, and the optical density (OD) at 450 nm is measured using a spectrophotometer. A standard curve is generated using a set of calibration standards, which allows the quantification of TGF-β in unknown samples based on their OD values. **Sample Collection and Storage:** - **Serum:** Use a serum separator tube. Allow samples to clot for 2 hours at room temperature or overnight at 4°C before centrifugation at 2000×g for 20 minutes. Remove serum and assay immediately, or aliquot and store at -20°C. Avoid repeated freeze-thaw cycles. - **Plasma:** Collect using heparin as an anticoagulant. Centrifuge within 30 minutes at 2000×g, 2–8°C. Avoid freezing and thawing. - **Cell culture supernatants, tissue homogenates, and other biological fluids:** Centrifuge to remove particulates. Assay immediately or store at -20°C. Ensure samples are properly centrifuged, with no hemolysis or debris present. **Materials Required (Not Supplied):** - 37°C incubator - Microplate reader capable of measuring absorbance at 450 nm - Precision pipettes, disposable tips, and absorbent paper - Distilled or deionized water **Reagents Provided (Stored at 2–8°C):** - MicroELISA strip plate (12×8 strips / 12×4 strips) - Standards (6 vials, 0.5 ml/vial) - Sample diluent (6.0 ml / 3.0 ml) - HRP-Conjugate reagent (10.0 ml / 5.0 ml) - 20X Wash solution (25 ml / 15 ml) - Chromogen A (6.0 ml / 3.0 ml) - Chromogen B (6.0 ml / 3.0 ml) - Stop solution (6.0 ml / 3.0 ml) - Closure plate membrane (2 pieces) - User manual (1 copy) - Sealed bags (1 pack) **Note:** Standard concentrations are 3200, 1600, 800, 400, 200, and 100 pg/mL. If sample values exceed the highest standard, dilute with sample diluent and repeat the assay. **Precautions:** - Do not mix reagents from different kits. All components are calibrated for optimal performance. - Allow all reagents and samples to reach room temperature (20–25°C) before use. Do not use water baths for thawing. - Do not use reagents beyond the expiration date. - Only use deionized water. - Keep microtiter plates in their sealed bag until needed. Store unused strips at 2–8°C with desiccant. - Use fresh pipette tips for each transfer. - Handle all biological samples as potentially infectious. Wear gloves during the procedure. - Dispose of waste after inactivation for at least 30 minutes. - Substrate solution is prone to contamination. Chromogen B contains 20% acetone—keep away from heat or flame. **Reagent Preparation:** - Wash solution (1X): Dilute 1 volume of 20X wash solution with 19 volumes of deionized or distilled water. Store at 2–8°C for up to one month. **Assay Procedure:** 1. Prepare standards and samples in duplicate. 2. Add 50 μL of standard or sample to appropriate wells. Blank well receives no addition. 3. Add 100 μL of HRP-conjugate reagent to all wells except blank. Cover with adhesive strip and incubate for 60 minutes at 37°C. 4. Wash microtiter plate 4 times manually or via automated washer. 5. Add 50 μL of chromogen A and 50 μL of chromogen B. Incubate for 15 minutes at 37°C, protecting from light. 6. Add 50 μL of stop solution. Color changes from blue to yellow. If uneven, gently tap the plate. 7. Read OD at 450 nm. Subtract blank OD from all readings. Plot standard curve and calculate sample concentration. **Performance Characteristics:** - Intra-assay CV <15%, Inter-assay CV <15% - Assay range: 100 pg/mL – 3200 pg/mL - Sensitivity: <100 pg/mL - Cross-reactivity: No significant cross-reaction with other proteins - Storage: 2–8°C (frequent use), 6 months at -20°C **Important Notes:** - Each user should generate their own standard curve. - Variations in technique, incubation time, or temperature may affect results. - Always follow good lab practices and handle all samples with care. **For Research Use Only. Not for diagnostic or therapeutic purposes.**

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