Protocol for re-suspension of Amyloid Beta Peptide 1-42 (HFIP treated), catalog# SPR-485

Dried Aβ 1-42 peptide has been pre-treated with hexafluoroisopropanol (HFIP) to disrupt any fibrils formed after peptide synthesis. We recommend re-suspended peptide is kept on ice and used immediately to avoid aggregation. While several methods of monomer resuspension are detailed in the literature, we recommend the following protocol for re-suspending 1.0 mg of peptide into a 1 mg/mL solution (scale the protocol appropriately for smaller aliquots):

1. Bring dried peptide to room temperature for 10 minutes.
2. Freshly open a sealed vial of DMSO (Sigma Hybri-Max D2650). Fresh DMSO is critical as it will absorb water over time, which can affect re-suspension as soluble monomer.
3. Add 20 uL fresh DMSO to peptide aliquot, mix well by pipetting up and down. Take care to scrape inside lower walls of tube to ensure complete re-suspension of the film. Do not store DMSO stock on ice as it will freeze.
4. Vortex DMSO stock for 10 seconds, bath sonicate for 10 minutes.
5. Add 980 uL of cold filter sterilized dH2O. Optional – Centrifuge monomer 14,000 x g for 5 minutes at 4oC and keep supernatant to remove any material that was not fully re-suspended.
6. Keep monomer on ice and use immediately.

While it is not recommended, depending on your application, small aliquots (≤ 50 μL) can be frozen and kept up to 2 weeks at -80, however aggregate should be removed by centrifugation at 4oC upon thawing.