• Assay Type

  Solid Phase Sandwich ELISA

• Format

  96-well strip plate

• Sample Type & Volume Required

  100 µL

• Range

  31.20 - 2,000 pg/mL

• Sufficient Materials

  For five 96-well plates*

• Specificity

  Please see the

* Provided that the recommended microplates, buffers, diluents, substrates and solutions are used, and the assay is run as summarized in the Assay Procedure provided.

Ancillary Reagent Kit Available  

DY008, DuoSet ELISA Ancillary Reagent Kit 2 -

This DuoSet ELISA Development kit contains the basic components required for the development of sandwich ELISAs to measure natural and Recombinant

Product Features

• Optimized capture and detection antibody pairings with recommended concentrations save lengthy development time

• Development protocols are provided to guide further assay optimization

• Assay can be customized to your specific needs

• Economical alternative to complete kits

Kit Content

• Capture Antibody

• Detection Antibody

• Recombinant Standard

• Streptavidin conjugated to horseradish-peroxidase (Streptavidin-HRP)

Other Reagents Required

  PBS: (Catalog # ), or 137 mM NaCl, 2.7 mM KCl, 8.1 mM Na  ₂HPO  ₄, 1.5 mM KH  ₂PO  ₄, pH 7.2 - 7.4, 0.2 µm filtered  
 
  Wash Buffer: (Catalog # ), or equivalent  
 
  Reagent Diluent*  
 
  Blocking Buffer*  
 
  Substrate Solution: 1:1 mixture of Color Reagent A (H  ₂O  ₂) and Color Reagent B (Tetramethylbenzidine) (Catalog # )  
 
  Stop Solution: 2 N H  ₂SO  ₄ (Catalog # )  
 
  Microplates: R&D Systems (Catalog # ), or equivalent  
 
  Plate Sealers: ELISA Plate Sealers (Catalog # ), or equivalent  
 

*For the Reagent Diluent and Blocking Buffer recommended for a specific DuoSet ELISA Development Kit, please see the product

Preparation and Storage

• Storage

  Store the unopened product at 2 - 8 °C. Do not use past expiration date.

Background: R-Spondin 4

R-Spondin 4 (RSPO4, roof plate-specific spondin 4), also called cysteine-rich and single thrombospondin domain containing-4 (Cristin 4), is an ~33 kDa secreted heparin-binding protein that shares ~35% amino acid (aa) identity with three other R-Spondin family members. All are positive modulators of Wnt/beta-Catenin signaling, but vary in activity. R-Spondins regulate Wnt/beta-Catenin by competing with the Wnt antagonist DKK-1 for binding to the Wnt co-receptors LRP-6 and Kremen, reducing their DKK-1-mediated internalization. Like other R-spondins, human R-Spondin 4 (228 aa) contains a signal sequence (aa 1-19), two adjacent cysteine-rich furin-like domains (aa 85-128) with one potential tyrosine phosphorylation site (aa 114), followed by a thrombospondin (TSP-1) motif (aa 137-197) and a region rich in basic residues (aa 199-228). Mature human R-Spondin 4 shares 81%, 81%, 84%, 84% and 86% aa identity with mouse, rat, equine, canine and bovine R-Spondin 4, respectively. Of two potential isoforms, one lacks the TSP-1 domain, while another terminates at aa 224. Each R-Spondin has a distinct expression pattern. In the mouse, R-Spondin 4 mRNA is found during development of limb bud mesenchyme, nail beds, heart and teeth. In humans, mutations of R-Spondin 4 have been found to cause anonychia, a condition in which fingernails and toenails are absent.

• Entrez Gene IDs:

  343637 (Human); 228770 (Mouse);

• Long Name:

  Roof Plate-specific Spondin 4

• Aliases:

  C20orf182; chromosome 20 open reading frame 182; Cristin 4; CRISTIN4; dJ824F16.3; FLJ16018; hRspo4; Roof plate-specific spondin-4; RSPO4; RSpondin 4; R-Spondin 4; R-spondin family, member 4; R-spondin-4