We can. But its not realistic. You need purified water, media, etc to grow the strain, you need waste disposal for when you purify the harvest. And the biggest bug bear - maintaining sterility for all the pieces of equipment, and the environment to. I suppose you could design it to be a single use, closed system. But even then, the challenges are enormous. I work in pharma and producing vaccines in a clean-room is challenging enough. The FDA can shut you down for a single OOS/OOT. I would never in a million years inject myself or anyone I know with something made from a DIY kit like that.