Hormones & Steroids

Pregnancy Associated Plasma Protein-A (PAPP-A) Pregnancy associated plasma protein-A (PAPP-A) is as a glycoprotein found in the serum of pregnant women. It is produced by the placenta and circulates in the form of a heterotetramer complexed with eosinophil major basic protein (proMBP). Its main role in pregnancy is to prevent the recognition of the fetus by the maternal immune system. In non-pregnant individuals, PAPP-A can also be produced by several cell types and detected at much lower levels (and in the form of a homodimer). Studies have shown that it can also be used as a potential biomarker for plaque instability in cardiac disease. In the first trimester of pregnancy, PAPP-A assays are used in conjunction with hCG or free beta hCG to screen for Down syndrome (Trisomy 21) and Edward’s syndrome (Trisomy 18). A low PAPP-A level can also be associated with pregnancy complications such as fetal growth restriction, fetal demise, preterm birth, and pre-eclampsia in the third trimester. As a cardiac marker, high PAPP-A serum levels indicate a risk for acute coronary syndromes (unstable angina and acute myocardial infarction), as PAPP-A is expressed by unstable and ruptured coronary artery plaques, but not stable plaques. Serum PAPP-A assays are based the two site sandwich immunoassay principles. For developing PAPP-A pregnancy diagnostics, antibodies that detect the heterotrimeric form (htPAPP-A/proMBP complex) must be used whereas antibodies that detect the homodimeric subunit dPAPP-A should be used for cardiac assays.

Reagents for Immunoassay Development


MAb to PAPP-A (proMBP) • Detection Antibody


MAb to PAPP-A • Recognizes human PAPP-A subunit of htPAPP-A • Can detect htPAPP-A and dPAPP-a in sandwich immunoassay when paired with Catalog #E86901M • Capture antibody MAb to PAPP-A • Recognizes human PAPP-A subunit of htPAPP-A • Detection antibody PAPP-A Native Antigen • Represents a heterotetrameric complex consisting of PAPP-A and pro-MBP subunits • Sourced from pooled human retroplacental blood • Lyophilized from 10 mM Tris-HCl, 0.15 M Sodium Chloride, pH 7.5

Suitable for use in ELISA





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