At what temperature should FITC-avidin be stored for FISH procedures?

The appropriate storage temperature for FITC-avidin, especially in the context of Fluorescence In Situ Hybridization (FISH) procedures, is 4°C. This temperature is optimal for maintaining the stability and functionality of the protein, which is crucial for ensuring effective binding to biotinylated probes during the hybridization process in FISH. Storing FITC-avidin at 4°C slows down degradation and maintains the integrity of its fluorescent properties, allowing for reliable results during analysis.

Storing FITC-avidin at -20°C may lead to issues such as freeze-thaw cycles that can denature the protein. Similarly, room temperature (25°C) could cause the protein to degrade over time due to temperature instability, while storage at 37°C is not recommended as it significantly increases the risk of denaturation and loss of activity. Keeping FITC-avidin at 4°C helps ensure that the reagent remains effective and provides accurate, reliable staining results in cytogenetic studies.