The hint says: that there is a key in the kitchen.
The key has a name, all the keys in the shelter have a name.
The name of the key says what it opens.
The key name is: Special box chamber 01.
The shelter has 6 chambers if you click on the chamber door on floor A.
All doors have a special box, with the name "Zip" written on the side of the 2 places to put the fuse.
Inside the Special box of the chamber 01, contain the Access card to the Bio Lab.


To have access to the Bio Lab, you need a Bio Lab access card.
This card is inside a box named "ZIP", at the door of the MC's chamber.
Not the door of the entrance of Chambers, but the door of the Chamber 01.
But to open this box you need a key, that is inside one of the drawers of the kitchen.

If you start a new game using the same name as an old save, it will not delete correctly your files from the old save, so if you have already taken the key in the kitchen in the old save the drawer in the kitchen that contains the key will be empty.
If the drawers are all empty, and you can't click on them, and this is the first time you enter the kitchen, it was because of this.