DESCRIPTION

CD40, also named as TNFRSF5 and Bp50, is a type I transmembrane protein that belongs to the tumor necrosis factor receptor (TNFR) family. CD40 is expressed on B cells, dendritic cells (DCs), monocytes, platelets, and macrophages as well as by nonhematopoietic cells such as myofibroblasts, fibroblasts, epithelial, and endothelial cells. It is a receptor for TNFSF5/CD40L. CD40L/CD40 interactions are essential for immunoglobulin (Ig) isotype switching, germinal center formation and the development of B cell memory.

PRINCIPLE OF THE ASSAY

Sandwich ELISA structure (Detection antibody labeled with HRP) A capture antibody is pre-coated onto the bottom of wells which binds to analyte of interest. A detection antibody labeled with HRP also binds to the analyte. TMB acts as the HRP substrate and the solution color will change from colorless to blue. A stop solution containing sulfuric acid turns solution yellow. The color intensity is proportional to the quantity of bound protein which is measurable at 450 nm with the correction wavelength set at 630 nm.

PRECISION

Intra-assay Precision (Precision within an assay) Three samples of known concentration were tested 8 times on one plate to assess intra-assay precision. Inter-assay Precision (Precision between assays) Three samples of known concentration were tested in 16 separate assays to assess inter-assay precision.

Intra-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	8	1,113.4	40.9	3.7
2	8	264.9	9.3	3.5
3	8	132.7	3.7	2.8

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	1,129.8	41.2	3.6
2	16	268.9	10.2	3.8
3	16	132.7	4.0	3.0

RECOVERY

The recovery of mouse CD40 spiked to three different levels throughout the range of the assay in various matrices was evaluated.

Sample Type		Average% of Expected	Range (%)
Mouse serum	1:2	78	77-81
Cell culture supernatant	1:2	96	87-111
Tissue lysate	1:20	79	72-88

LINEARITY

To assess the linearity of the assay, mouse serum and cell culture supernatant samples were spiked with high concentrations of mouse CD40 and diluted with the appropriate Sample Diluent to produce samples with values within the dynamic range of the assay. Tissue lysate samples were diluted with the appropriate Sample Diluent to produce samples with values within the dynamic range of the assay. (The tissue lysate was initially diluted 1:2.5.)

		Mouse serum	Cell culture supernatant	Tissue lysate
1:2	Average% of Expected	100	105	100
	Range (%)	100-101	100-116	-
1:4	Average% of Expected	98	103	101
	Range (%)	97-99	98-114	80-113
1:8	Average% of Expected	100	107	110
	Range (%)	99-101	99-121	77-128
1:16	Average% of Expected	97	104	106
	Range (%)	97-98	97-117	71-125

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant mouse CD40 produced at Sunlong Medical™.

Ordering & shipping

• Minimum order: 1 kit
• Lead time: varies with order quantity and specifications. Please consult your local distributor or our sales team for confirmation
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• Shipping: FedEx / DHL / UPS express; cold-chain packing available on request
• Price: USD, per kit (48T / 96T options available)