DESCRIPTION

The CD40 ligand (CD40L), also known as TRAP or CD154, is a member of the TNF superfamily of ligands. CD40L is primarily expressed on activated CD4+ T cells and on a small proportion of CD8+ T cells and platelets. It binds to CD40 on antigenpresenting cells (APC), which leads to many effects depending on the target cell type. It has been suggested that CD40/CD40L interactions regulate oxidative stress and affect various signaling pathways in both the immunological and the cardiovascular systems. The CD40/CD40L system is also involved in tumorigenesis. Its expression is tightly regulated, and abnormal levels of CD40L are associated with the pathogenesis of atheromatous plaque destabilization and thrombotic events. Multiple mutations in CD40LG gene have been identified that are associated with hyper-IgM immunodeficiency syndrome type 1. Apart from the 33 kDa transmembrane form, a soluble form of CD40L generated by ectodomain shedding has been reported.

PRINCIPLE OF THE ASSAY

Sandwich ELISA structure (Detection antibody labeled with biotin) A capture antibody is pre-coated onto the bottom of wells which binds to analyte of interest. A detection antibody labeled with biotin also binds to the analyte. Streptavidin-HRP binds to the biotin. 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 20 times on one plate to assess intra-assay precision. Inter-assay Precision (Precision between assays) Three samples of known concentration were tested in 24 separate assays to assess inter-assay precision.

Intra-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	20	892.2	18.7	2.1
2	20	211.2	6.0	2.8
3	20	47.0	1.7	3.6

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	24	931.2	25.5	2.7
2	24	220.1	4.7	2.1
3	24	51.2	3.1	6.1

RECOVERY

The recovery of human CD40 ligand/CD154 spiked to three different levels throughout the range of the assay in various matrices was evaluated.

Sample Type		Average% of Expected	Range (%)
Human plasma	1:4	99	91-119
	1:8	91	75-107

LINEARITY

To assess the linearity of the assay, human serum samples were diluted with the appropriate Sample Diluent to produce samples with values within the dynamic range of the assay.

		Human serum
1:4	Average% of Expected	100
	Range (%)	-
1:8	Average% of Expected	92
	Range (%)	80-100
1:16	Average% of Expected	89
	Range (%)	84-99
1:32	Average% of Expected	84
	Range (%)	76-89

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human Human CD40 ligand/CD154 Sandwich ELISA Kit 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
• Payment: T/T 100% in advance; PayPal; Alibaba Trade Assurance
• Shipping: FedEx / DHL / UPS express; cold-chain packing available on request
• Price: USD, per kit (48T / 96T options available)