I'm planning to use THLE-2,3 cells for my studies. I heard that they are genetically modified. Do I have to get a bio-safety certificate before using them? If yes, please suggest some other normal human cell lines.
It may be a good idea to check the requirements with your own institution before putting your plans into action.
Generally speaking, immortalized cells are modified in some way or another and most institutions have safety policies in place to which one must comply.
You can visit and learn a fair bit about these cells from ATCC's website. If you are planning to purchase them from ATCC, without a written proof of your ability to conform to all safety requirements, they will not sell these cells to you. On the other hand, if you are interested in working with any transformed cell lines, why would you not wish to follow necessary biosafety precautionary measures?