Refer to the product for complete assay procedure. Bring all reagents and samples to room temperature before use. It is recommended that all samples, standards, and controls be assayed in duplicate. Prepare all reagents, standard dilutions, and samples as directed in the product insert. Remove excess microplate strips from the plate frame, return them to the foil pouch containing the desiccant pack, and reseal. 100 µL Assay Diluent Add 100 µL of the appropriate Assay Diluent to each well. 100 µL Standard, Control, or Activated Sample Add 100 µL of Standard, control, or activated sample to each well. Cover with a plate sealer, and incubate at room temperature for 2 hours. Aspirate each well and wash, repeating the process twice for a total of 3 washes. 200 µL Conjugate Add 200 µL of Conjugate to each well. Cover with a new plate sealer, and incubate at room temperature for 2 hours. Aspirate and wash 3 times. 200 µL Substrate Solution Add 200 µL Substrate Solution to each well. Incubate at room temperature for 20 minutes. PROTECT FROM LIGHT. 50 µL Stop Solution Add 50 µL of Stop Solution to each well. Read at 450 nm within 30 minutes. Set wavelength correction to 540 nm or 570 nm. . Formulation: Lyophilized from a 0.2 μm filtered solution in Acetonitrile and TFA with BSA as a carrier protein. Reconstitution: Purified recombinant human TGF-beta 1 is an extremely hydrophobic protein that adheres strongly to surfaces.. The Quantikine Human TGF-beta 2 Immunoassay is a 4.5 hour solid-phase ELISA designed to measure activated TGF-beta 2 in cell culture supernates, serum, and plasma..