Products

Human SP-D(Pulmonary surfactant-associated protein D) ELISA Kit
ELK8561
Size: Price:
48 T $265.00
96 T $376.00

Overview

Product name: Human SP-D(Pulmonary surfactant-associated protein D) ELISA Kit
Reactivity: Human
Alternative Names: SFTPD; SPD; SFTP 4;
Assay Type: Sandwich
Sensitivity: 0.52 ng/mL
Standard: 80 ng/mL
Detection Range: 1.25-80 ng/mL
Sample Type: serum, plasma, tissue homogenates, cell lysates, lung lavage fluid, cell culture supernates and other biological fluids
Assay Length: 3.5h
Research Area: Infection immunity;Pulmonology;
Uniprot ID: P35247
Test principle: The test principle applied in this kit is Sandwich enzyme immunoassay. The microtiter plate provided in this kit has been pre-coated with an antibody specific to Human SP-D. Standards or samples are added to the appropriate microtiter plate wells then with a biotin-conjugated antibody specific to Human SP-D. Next, Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. After TMB substrate solution is added, only those wells that contain Human SP-D, biotin-conjugated antibody and enzyme-conjugated Avidin will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of sulphuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450nm ± 10nm. The concentration of Human SP-D in the samples is then determined by comparing the OD of the samples to the standard curve.

Standard curve

Concentration (ng/mL) OD Corrected OD
80.00 2.168 2.059
40.00 1.687 1.578
20.00 1.043 0.934
10.00 0.928 0.819
5.00 0.582 0.473
2.50 0.325 0.216
1.25 0.228 0.119
0.00 0.109 0.000

Precision

Intra-assay Precision (Precision within an assay):CV%<8%

Three samples of known concentration were tested twenty times on one plate to assess intra-assay precision.

Inter-assay Precision (Precision between assays):CV%<10%

Three samples of known concentration were tested in forty separate assays to assess inter-assay precision.

Recovery

Matrices listed below were spiked with certain level of recombinant SP-D and the recovery rates were calculated by comparing the measured value to the expected amount of SP-D in samples.
Matrix Recovery range Average
serum(n=5) 77-95% 86%
EDTA plasma(n=5) 88-103% 95%
Heparin plasma(n=5) 92-106% 99%

Linearity

The linearity of the kit was assayed by testing samples spiked with appropriate concentration of SP-D and their serial dilutions. The results were demonstrated by the percentage of calculated concentration to the expected.
Matrix 1:2 1:4 1:8 1:16
serum(n=5) 83-95% 88-102% 85-97% 80-92%
EDTA plasma(n=5) 85-96% 87-101% 89-102% 85-98%
Heparin plasma(n=5) 86-95% 93-103% 85-94% 87-101%