Learn how to use this product Horse Serum has applications in cell culture studies as an alternative to bovine serum for growth factors and hormones, such as for the cultivation of hematopoietic stem cells and neuronal cells. It is also used for diagnostic assays. Furthermore, Horse Serum contains more immunoglobulins than Fetal Bovine Serum and has increased protein content. It is a cost-effective substitute for Fetal Bovine Serum.