Long-term Storage of Diluted Antibody in Tris-buffered Saline with Tween 20

Western blotting is a fundamental technique for protein detection and quantification, with critical dependence on antibody for its sensitivity and specificity. Antibody solutions are frequently reused to conserve the limited stock and compensate for their high cost. However, storing antibody solutions is often challenged by protein aggregation and loss of immunoreactivity, especially when skim milk is added. Recent advancements in Western blot include microfluidic techniques which minimize antibody consumption. To facilitate these techniques, a storage strategy is needed for diluted antibody solutions to properly preserve their immunoreactivity.

We found that Tris-buffered saline with 0.1% Tween 20 (TBST), an ordinary washing buffer for Western blot, provides protection to diluted antibodies for extended period of storage at 4 °C. We discovered that TBST-diluted commercial antibodies retained their immunoreactivity for 281 days at ambient temperature and 1,690 days at 4 °C. In addition, we demonstrated that Tween 20 plays a critical role in stabilizing the diluted antibody.

We propose that TBST is an effective and practical buffer to preserve diluted antibodies, which can be utilized as an integral part of strategies to reduce antibody consumption in laboratories.