Small Size and Scale-Up Issues: One of the main issues of animal cell culture is that cultures are usually done on a small scale, and they may be difficult to scale up for commercial or industrial level production.
May Not Represent In-Vivo: An important limitation of in vitro animal cell culture is that it may not accurately reflect the natural characteristics of the cells in vivo in the body. This is mainly because the lab environment is very different from what is found in the body.
Other relevant points: Any other valid point from the chapter.