Production and characterization of an antiserum against recombinant porcine follicle stimulating hormone

This study aimed to develop an antiserum specific to follicle stimulating hormone (FSH), for a wide range of species, free from cross-reactivity against luteinizing hormone. An antiserum against recombinant porcine FSH (rec-pFSH) expressed in insect cells was raised in a rabbit and its specificity was characterized by time-resolved fluoroimmunoassay (TR-FIA) and immunohistochemistry. The titer of the anti-rec-pFSH antiserum was about 1:5,000 for use in TR-FIA. The inhibition curve of TR-FIA with rec-pFSH paralleled that of pituitary-derived FSH, indicating that the antigenicities of the two FSH preparations do not differ significantly. The anti-rec-pFSH antiserum showed low reactivities with FSHs prepared from sheep and rat, suggesting it was species- and hormone-specific, contrary to our intention. The TR-FIA showed that this antiserum did not react with pituitary extracts from mammals other than the pig. However, immunohistochemistry demonstrated that this antiserum reacted with the specific cells not only of the porcine anterior pituitary but also of the cow, goat, and horse. The antiserum also immunostained pituitary cells of the cow, goat and horse. Therefore, this anti-rec-pFSH antiserum will be of limited use in studies involving competitive immunoreactions due to its species-specific reactivity, but it should be useful for non-competitive techniques, such as immunohistochemistry.