Fluorescein-12-UTP is ideal for in vitro transcription reactions catalyzed by T3, T7, or SP6 RNA polymerases and reverse transcriptase to produce fluorophore-labeled RNA transcripts. RNA-based probes can be used to identify complementary sequences by in situ hybridization to fixed cells and tissues by direct or indirect fluorescence detection or by membrane hybridization procedures. Alternative Name: Fluorescein-12-uridine-5'-triphosphate. Formulation: Liquid. Solution in water. Purity: ≥93% (HPLC). Appearance: Yellow-green liquid and orange frozen solution. Use/Stability: Stable for at least one year after receipt when stored as recommended. Shipping: Shipped on Dry Ice. Long Term Storage: -20°C Excitation maximum: 496 nm Emission maximum: 520 nm. Handling: Protect from light. Avoid freeze/thaw cycles.