B-IgG-SAP

B-IgG-SAP (Blank-IgG-Saporin) is a non-targeted immunotoxin conjugate primarily utilized as a negative control in preclinical research, particularly in molecular neurosurgery and neurobiology. It consists of a non-specific immunoglobulin G (IgG) antibody—most commonly mouse IgG—covalently conjugated to saporin, a Type I ribosome-inactivating protein (RIP) derived from the soapwort plant (*Saponaria officinalis*). Saporin acts as an RNA N-glycosidase that irreversibly depurinates the sarcin/ricin loop of the 28S ribosomal RNA, thereby halting protein synthesis and inducing apoptotic cell death. Because the IgG component of B-IgG-SAP lacks a specific binding affinity for cell-surface receptors, the conjugate does not undergo efficient receptor-mediated endocytosis in healthy cells. It is used to establish a baseline for non-specific cellular uptake, the inherent toxicity of the saporin payload, and the physical effects of the administration procedure in experimental models of neurodegenerative conditions, such as Alzheimer's disease, where targeted conjugates like 192-IgG-SAP are employed to lesion specific neuronal populations.

Other names

IgG-SAPNon-targeted saporin conjugateMouse IgG-saporinBlank-SAP