Designing and Developing Enzyme-Linked Immunosorbent Assay Sandwich Kit for Measuring Placental Growth Factor Concentration.

Placental growth factor (PlGF) is an angiogenic factor belonging to vascular endothelial growth factor family. This factor is mainly expressed in the placenta and have important role in blood supply to embryonic tissues and fetal. According to accumulated data after 10th week of gestational age the expression of PlGF is increased. The peak of this factor is seen in the 30th week of pregnancy. The abnormal expression of PlGF have been seen in some diseases such as preeclampsia, eclampsia, cancer, and atherosclerotic lesions. Preeclampsia is a pregnancy complication characterized by high blood pressure and signs of damage to another organ system, most often the liver and kidneys. As noted the level of PlGF decreased in preeclampsia is, therefore, timely and accurate measurement of this factor could help in diagnosing preeclampsia. In this study, we worked on development of sandwich enzyme-linked immunosorbent assay (ELISA) kit for measurement of PlGF, to this end, bivalent single-domain monoclonal antibody with high affinity binding was used as detection antibody and rabbit polyclonal antibody with strong signal to PlGF was used as capture antibody. Both types of antibodies were produced in the laboratory. Therefore, this study showed that the designed kit can measure PlGF up to 7.5 pg/mL. Intra-assay accuracy was <10% and interassay accuracy was <15%. The ELISA sandwich kit had the appropriate sensitivity and accuracy in measuring human PlGF.