Question 1: Can the reconstituted ATP be stored at 4°C for any length of time or does it need to be immediately snap-frozen?
Answer 1: The ATP ((Cat. #BSA04) should be reconstituted to 100 mM with 1 ml of cold 100 mM Tris, pH 7.5. Set aside the volume that is needed for the day&rsquo, s experiment (stable for 4 h on ice) and the remaining ATP should then be aliquoted into experiment-sized amounts, snap frozen in liquid nitrogen, and stored at or below -20°C. These stocks are stable for 6 months at -20°C.
Question 2: How long are solutions with ATP in them stable at 4°C if performing actin polymerization experiments?
Answer 2: Buffers containing ATP ((Cat. #BSA04) will be stable for 4 h on ice. Keep on ice until ready to use. After 4 h discard the tube, do not re-freeze to use later. Prepare fresh buffers (or freshly frozen aliquot) for the next experiment.