My guess: non trivial to do it safely and non trivial to get accuracy rates you'd get from a professional lab. Doing all those things by hand also takes some t

My guess: non trivial to do it safely and non trivial to get accuracy rates you'd get from a professional lab. Doing all those things by hand also takes some time. Thinking back to my days in a lab at MIT, sample to PCR probably took a full day (rough approximation). Big labs can probably increase the parallelism a lot.