Do I have to add serum, growth factors, or supplements to the cell suspension before mixing with VitroGel?

No. Adding supplements to the hydrogel matrix is not required. For most xenograft applications, preparing cells in PBS solution works exceptionally well with VitroGel. On the other hand, VitroGel is animal-origin free, which gives the flexibility for researchers to manipulate the supplement in a gel-cell mixture if needed.