MALP-2 (BULK)

As indicated on product label or CoA when stored as recommended. Stable for at least 3 years when stored at -20°C. This stock solution is stable for many months when kept in the refrigerator. MALP-2 solutions in the presene of carrier (50mM octyl glucoside, see Background/Technical Information below) are stable at +4°C at least 6 weeks. Some (10%) decrease of activity may occur shortly after transfer into new vessels. This is not due to decomposition but to adsorption (see below) . Storage at room temperature for short periods of time does not influence bioactivity. When deep-frozen, MALP-2 does not loose activity within years.

MALP-2 sticks avidly to glass or plastic. Since it is active at very low concentrations, i.e. at high dilutions, these low amounts of material tend to become adsorbed to pipette tips and plastic or glass containers. To avoid this, prepare several dilution steps of the MALP-2 stock solution with medium containing 5% autologous serum or buffers with 2% HSA. The presence of 50mM octyl glucoside in the first dilution step is often beneficial and gives rise to higher activity. Avoid small volumes in large vessels. Do not filter.Because of the ester-bound fatty acids, MALP-2 is sensitive to alkali or acid. The medium should be preconditioned in the CO 2 incubator in order to ensure that the pH does not become alkaline. Add cells in preconditioned medium as soon as possible and incubate.