HtrA3 ELISA Assay Kit


The HtrA3 ELISA Assay Kit provides a highly sensitive and specific quantitative determination of HtrA3 in serum, tissue (Placenta) and cell culture supernatants. The Eagle Biosciences HtrA3 ELISA Assay Kit is for research use only and not to be used in diagnostic procedures.

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HtrA3 ELISA Assay Kit

The HtrA3 ELISA Assay Kit is For Research Use Only

Size: 1×96 wells
Sensitivity: 700 pg/mL
Dynamic Range: 0.78 ng/ml to 50 ng/ml
Incubation Time: 4.25 hours
Sample Type: Serum, tissue, cell culture supernatants
Sample Size: 100 µL
Controls Included

Assay Principle

This Eagle Biosciences HtrA3 ELISA is a quantitative assay that is based on a two site sandwich format. A highly specific monoclonal antibody against HtrA3 is immobilised on the plate. HtrA3 will be bound to the wells, other components of the sample are removed by discarding/drying by tapping and washing of the plate. The analyte is detected in two steps using a secondary biotin-labeled monoclonal antibody and a highly polymerised streptavidin-peroxidase conjugate. Any excess is removed by discarding/drying by tapping and washing after each detection step. The amount of peroxidase bound to each well is determined by the addition of TMB Substrate. The reaction is stopped by adding the Stop Solution and the yellow colour is read in a microtiter plate reader at 450 nm. The concentration of HtrA3 in a sample is determined by interpolation from the standard curve. One kit contains reagents for 96 determinations, thus allowing the measurement of one standard curve and 40 samples in duplicate.

Related Products

HtrA1 ELISA Assay Kit
HtrA4 ELISA Assay Kit
Universal Protease Activity ELISA

Additional Information

Assay Background

Human HtrA3 (high temperature requirement A3) is a serine protease of the HtrA family. HtrA3 was initially identified in the developing placenta both in mouse and in human as a serine protease associated with pregnancy [1]–[4]. HtrA3 is now known to inhibit trophoblast invasion during placental development [5], [6], and regulate ovarian development, granulosa cell differentiation and luteinisation [7], [8]. Studies in mice have also suggested that HtrA3 inhibits TGF-β signalling during embryo development [9]. It has two isoforms [long (HtrA3-L) and short (HtrA3-S)] and recently, HtrA3 was identified as a potential diagnostic marker for early detection of preeclampsia, a life-threatening pregnancy-specific disorder.


Product Documents



  • Nie GY, Hampton A, Li Y, Findlay JK, Salamonsen LA (2003) Identification and cloning of two isoforms of human high-temperature requirement factor A3 (HtrA3), characterization of its genomic structure and comparison of its tissue distribution with HtrA1 and HtrA2. Biochem J 371: 39–48. doi: 10.1042/bj20021569
  • Nie GY, Li Y, Minoura H, Batten L, Ooi GT, et al. (2003) A novel serine protease of the mammalian HtrA family is up-regulated in mouse uterus coinciding with placentation. Mol Hum Reprod 9: 279–290. doi: 10.1093/molehr/gag036
  • Nie G, Li Y, Hale K, Okada H, Manuelpillai U, et al. (2006) Serine peptidase HTRA3 is closely associated with human placental development and is elevated in pregnancy serum. Biol Reprod 74: 366–374. doi: 10.1095/biolreprod.105.047324
  • Nie G, Li Y, He H, Findlay JK, Salamonsen LA (2006) HtrA3, a serine protease possessing an IGF-binding domain, is selectively expressed at the maternal-fetal interface during placentation in the mouse. Placenta 27: 491–501. doi: 10.1016/j.placenta.2005.03.009
  • Singh H, Endo Y, Nie G (2011) Decidual HtrA3 negatively regulates trophoblast invasion during human placentation. Hum Reprod 26: 748–757. doi: 10.1093/humrep/der019
  • Singh H, Makino SI, Endo Y, Nie G (2010) Inhibition of HTRA3 stimulates trophoblast invasion during human placental development. Placenta 31: 1085–1092. doi: 10.1016/j.placenta.2010.10.003
  • Bowden M, Drummond AE, Salamonsen LA, Findlay JK, Nie G (2009) Evolutionary conservation of mammalian HTRA3 and its developmental regulation in the rat ovary. J Exp Zool B Mol Dev Evol 312: 701–713. doi: 10.1002/jez.b.21288
  • Bowden MA, Li Y, Liu YX, Findlay JK, Salamonsen LA, et al. (2008) HTRA3 expression in non-pregnant rhesus monkey ovary and endometrium, and at the maternal-fetal interface during early pregnancy. Reprod Biol Endocrinol 6: 22. doi: 10.1186/1477-7827-6-22
  • Tocharus J, Tsuchiya A, Kajikawa M, Ueta Y, Oka C, et al. (2004) Developmentally regulated expression of mouse HtrA3 and its role as an inhibitor of TGF-beta signaling. Dev Growth Differ 46: 257–274. doi: 10.1111/j.1440-169x.2004.00743.x PLoS ONE, 2012; 7(9): e45956. doi:10.1371/journal.pone.0045956
  • Dynon K, Heng S, Puryer M, Li Y, Walton K, et al. (2012) HtrA3 as an Early Marker for Preeclampsia: Specific Monoclonal Antibodies and Sensitive High Throughput Assays for Serum Screening. PLoS ONE, 7(9): e45956. doi:10.1371/journal.pone.0045956

Product Citations