Surfactant Protein D Human ELISA (SP-D)

Research topic

Infection and inflammation

Features

• The total assay time is about 20 hours.
• The kit measures total Surfactant Protein D.
• Standards are human recombinat protein based.
• Quality Controls are human recombinant protein based.
• No animal sera are used.

Storage/Shipping

Store the kit at 2–8°C. Under these conditions, the kit is stable until the expiration date (see label on the box).

Summary

SP-D is a homotrimeric protein consisting of three 43kDa units, that are bonded at their N-termini. Most preparations of SP-D contain predominantly dodecamers (four trimeric subunits), but also higher multimers have been observed. Each unit consists of at least four discrete structural domains: a short N-terminal domain; a relatively long collagenous domain, a short amphipathic connecting peptide, and a C-terminal, C- type lectin carbohydrate recognition domain (CRD). In the lungs, SP-D participates in the innate response to inhaled microorganisms and organic antigens. SP-D binds to surface glycoconjugates of various microorganisms and to oligosaccharides associated with the surface of numerous organic antigens. Studies have shown that SP-D expression may be related to a number of human diseases: cystic fibrosis, acute interstitial pneumonias (ARDS), asthma, bronchopulmonary dysplasia, alveolar proteinosis etc.

Assay format

Sandwich ELISA, HRP-labelled antibody

Sample requirements

10 µl/well

Applications

Amniotic fluid, Bronchoalveolar lavage, Cell culture medium, Plasma-Citrate, Plasma-EDTA, Plasma-Heparin, Serum

Calibration Curve

Calibration range

1.56 – 100 ng/ml

Limit of detection

Analytical Limit of Detection is calculated from the real human SP-D values in wells and is 0.2 ng/ml

Limit of quantification

Assay Sensitivity takes the dilution of samples into consideration and is calculated according to the formula: Assay Sensitivity = Analytical Limit of Detection x sample dilution = 0.2 ng/ml x 11 = 2.2 ng/ml

Intra-assay (Within-Run, n=8)

CV = 3.5 %

Inter-assay (Run-to-Run, n=4)

CV = 7.2 %

Spiking Recovery

93.2 %

Dilution Linearity

103.2 %

Cross-Reactivity

Human, Horse, Monkey, Pig

References to this product

• Sims MW, Tal-Singer RM, Kierstein S, Musani AI, Beers MF, Panettieri RA, Haczku A. Chronic obstructive pulmonary disease and inhaled steroids alter surfactant protein D (SP-D) levels: a cross-sectional study. Respir Res. 2008;9:13
• Nickmilder M, Carbonnelle S, Bernard A . House cleaning with chlorine bleach and the risks of allergic and respiratory diseases in children. Pediatr Allergy Immunol . Feb;18(1):27-35 (2007)
• Schnapp LM, Donohoe S, Chen J, Sunde DA, Kelly PM, Ruzinski J, Martin T, Goodlett DR . Mining the acute respiratory distress syndrome proteome: identification of the insulin-like growth factor (IGF)/IGF-binding protein-3 pathway in acute lung injury. Am J Pathol . Jul;169(1):86-95 (2006)
• Sorensen GL, Husby S, Holmskov U . Surfactant protein A and surfactant protein D variation in pulmonary disease. Immunobiology . 212(4-5):381-416 (2007)
• Erpenbeck VJ, Ziegert M, Cavalet-Blanco D, Martin C, Baelder R, Glaab T, Braun A, Steinhilber W, Luettig B, Uhlig S, Hoymann HG, Krug N, Hohlfeld JM . Surfactant protein D inhibits early airway response in Aspergillus fumigatus-sensitized mice. Clin Exp Allergy . 36(7):930-40 (2006)

References to summary

• Crouch E.C: Surfactant protein-D and pulmonary host defense. Respir Res, 1(2):93–108, (2000)
• Honda Y., Kuroki Y., Matsuura E., et al.: Pulmonary surfactant protein D in sera and bronchoalveolar lavage fluids. Am. J. Respir. Crit. Care Med., 152: 1860–1886, (1995)
• Inoue T., Matsuura E., Nagata A. et al.: Enzyme- linked immunosorbent assay for human pulmonary surfactant protein D. J. Immunol. Methods, 173: 157–164, (1994)
• Takahashi H., Kuroki Y., Abe S at al.: Serum Surfactant Proteins A and D as Prognostic Factors in Idiopathic Pulmonary Fibrosis and Their Relationship to Disease Extent. Am. J. Respir. Crit. Care Med., 162: 1109–1114, (2000)
• Ohnishi H., Hiwada K., Kohno N. et al.: Comparative Study of KL-6, Surfactant Protein-A, Surfactant Protein D, and Monocyte Chemoattractant Protein –1 as Serum Markers for Interstitial Lung Diseases. Am. J. Respir. Crit. Care Med., 165: 378–381, (2002).