Serum contains all the clotting factors, except
If whole blood is allowed to clot and the clot is removed, the remaining fluid is called serum. Serum has essentially the same composition as plasma, except that:

Fibrinogen (factor I) and clotting factors II, V, and VIII have been removed and
Has higher serotonin content, because of the breakdown of platelets during clotting.

Also, know that factor 5 is called as labile factor.
Plasma thromboplastin
Labile factor
Hageman factor
Christmas factor