I've been doing experiments for at least three years.I have met so many difficulties.Every time I reflect on myself whether I suit doing experiments or not.People who are not in this industry cannot figure out what a bad feeling it is.A laboratory technician need so much patient and experience.The experiment has double faces.When you get what you expect,it gives you satisfaction,but the most time the experiment result can be very bad.At that time you may feel so disappointed and even hate the experiment,because it wastes lots of your time.It can be called  torment.That's why much people give up engaging experiments relative work when they got master degree.While, the Phds are not included in this bound.