Why is it difficult to recruit people for protein purification positions?

The interview is difficult and there are few positions.

1. protein purification job interview. During the interview, I interviewed the director of cell first, mainly about the above problems of protein purification. How to purify it, what is the principle, and the method and principle of protein crystallization are all in-depth.

2. There are few positions. 202 1, the post of purification technicians in protein is only 1 10.