All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
First of all, may Allaah reward you for being keen on abiding by the rulings of the Sharee’ah and for fearing to do what angers Allaah. We ask Allaah to make you firm on His Religion and enable you to do whatever pleases Him.
You should know that if the job of a woman necessitates being in seclusion with non-Mahram men, or touching them, or mixing with them in a way that causes temptation, then this job is not permissible. Therefore, if your job subjects you to treat men and this requires mixing with them and touching them without a necessity, then this is not permissible.
As regards your work in a laboratory, if you are not exposed to being in seclusion with non-Mahram men, and you are safe from being tempted in your religion, then this job is permissible and we advise you to do it.
It should be noted that working as a pediatrician is better than working in adult medicine. So, if you cannot find work in a laboratory, then working as a pediatrician is better, while endeavoring to keep away from reasons of temptation. For more benefit on the pre-conditions for women to work, please refer to Fatwa 83607.
Finally, we stress that it is not permissible for a woman to shake hands with a non-Mahram man; for more benefit in this regard, please refer to Fatwa 82318.
Allaah Knows best.