Biotechnology Careers Malaysia

I do not know much about neither the Malaysian job situation, nor any of those fields of study you have mentioned. Therefore I ran a quick search on a job site in Malaysia, and it was pretty clear that there were more job posts on electrical engineering than biotechnology. While jobs in the field of biotechnology was limited to 30, I found 819 jobs in electrical engineering. This might indicate that a lot of the jobs in biotechnology is being offered internally in the society of biotechnology, and it might not be so easy to get in that circle.
From this fact, and also the fact that you would be able to do you own electricity and wiring (which in Denmark where I live is pretty expensive!!), I would choose a career in electrical engineering. But this is only if I had to decide from the hard facts.
When I chose my field of study, I chose solely from what interested me. I think you should do the same. The payment and prestige is nothing, if you are not interested in what you are doing. If you are in doubt about what you like the most, I would recommend talking to a student counselor. That helped me a lot.
One last advise is to try and get a job as a student assistant in some company, that is working in the same field as you are studying. Payed or unpayed, this will give you a lot of work related experience, and a foot inside the door, so that you will have an easier time getting a job after your education ends.