We buy our Tunicamycin from EMD and dissolve the whole vial as 5 mg/ml stock in sterile DMSO. Then we aliquot in 500ul aliquots and flash freeze. Then we thaw a 500ul aliquot and sub aliquot into 10ul aliquots and flash freeze those, which are single use. We can send you tunicamycin if you don’t want to have to buy your own.
For the experiment, we inject mice with either Tunicamycin or an equal volume of DMSO dissolved in 150 mM dextrose (PBS also works). We like to inject with 250 ng/g bodyweight, so we dilute the tunicamycin or DMSO 1/200 in the dextrose and then inject with 10ul per gram. Thus, a 20g animal gets 200ul, or 5ug of the tunicamycin solution. We inject IP.
We usually sacrifice the animals ~12-16h after the injection. You might want to do the injection so that the harvest is at the end of the dark cycle, so that the animals will be well-fed, which might raise the chance that a difference in Fasn will matter. We normally fast animals 4h before sacrifice, but I wouldn’t recommend it here for the same reason.
Usually for Tunicamycin gender doesn’t matter. We like to use animals 6-8 weeks old, but older is usually OK. You would need ~16 animals: 8 wild-types and 8 controls, of which 4 each get tunicamycin or vehicle.