Hello Marine Ma,

For COL4A1 and COL4A2, the solubility is pH-dependent, with these exhibiting high solubility in acidic solutions like acetic acid. Lyophilized COL4A1 and COL4A2 can be reconstituted in 0.5 M acetic acid. This process is a standard technique of preparation for various applications, including cell culture. Lyophilized type IV collagen (COL4A1 and COL4A2) is often not readily soluble in water or PBS as it will not form a clear, soluble solution, instead it typically reconstitutes into a slightly hazy solution or suspension. The low pH of acetic acid helps maintain the triple-helical structure of the collagen fibers, preventing them from denaturing or aggregating.

Protocol in brief.

1. Sterile cold 0.5 M acetic acid is added to the lyophilized collagen powder. (Please note: To prevent thermal denaturation, the 0.5 M acetic acid should be sterile and cold (2–8°C)).

2. The mixture is gently swirled or agitated at 2–8°C for several hours or overnight until the powder is fully dissolved. (Please note: Vigorous mixing or vortexing should be avoided to prevent denaturation).

Best,

Protein in the form of lyophilized powder: take 10 μg as an example,

① Add 20 μL of ddH2O; Pipette blowing to fully dissolve;

② Add 80 μL buffer/medium containing carrier protein (0.1% BSA, 5% HSA, 10% FBS, or 5% trehalose), and mix with pipette; The final concentration is not less than 100 μg/mL;

③ sub-pack 20 μL/ tube;

④ After sub-pack, frozen in -20ºC ~ -80ºC, and protein can be stored for 3~6 months. For details, see Article 8 of the Handling Instructions on our website. https://file.medchemexpress.com/instructions-for-usage-of-recombinant-protein.pdf

The answer to this question is provided by MedChemExpress Technical Support. [email protected]