DESCRIPTION

E-selectin (Endothelial Leukocyte Adhesion Molecule-1, also known as CD62E) is a critical adhesion molecule expressed on endothelial cells. It plays a crucial role in the initial steps of leukocyte recruitment to sites of inflammation, facilitating the rolling and adhesion of leukocytes to the endothelium. This process is essential for the immune response to infection and injury. E-selectin is upregulated in response to inflammatory cytokines such as IL-1, TNF-α, and bacterial lipopolysaccharide (LPS), and it interacts with various glycan ligands on leukocytes, including PSGL-1, ESL-1, CD44, and CD43.

PRINCIPLE OF THE ASSAY

An anti-tag antibody is pre-coated onto the bottom of wells. After adding antigen or samples, Tagged-Capture antibody and HRP-conjugated detection antibody, a sandwich complex is formed in the solution. TMB acts as a HRP substrate, and the solution color will change from colorless to blue. A stop solution containing sulfuric acid turns the 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	515.4	11.3	2.2
2	8	133.5	3.5	2.6
3	8	39.8	1.6	4.0

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	515.0	10.1	2.0
2	16	133.6	3.9	2.9
3	16	39.7	1.8	4.5

RECOVERY

The recovery of human E-selectin/CD62E spiked to three different levels throughout the range of the assay in human plasma was evaluated.

Sample Type		Average% of Expected	Range (%)
Human plasma	1:320	111	105-118
	1:640	97	71-119

LINEARITY

To assess the linearity of the assay, samples were diluted with the appropriate Sample Diluent to produce samples with values within the dynamic range of the assay. (The human plasma was initially diluted 1:40.)

		Human plasma
1:2	Average% of Expected	100
	Range (%)	-
1:4	Average% of Expected	101
	Range (%)	100-102
1:8	Average% of Expected	108
	Range (%)	107-109
1:16	Average% of Expected	113
	Range (%)	112-113

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human Human E-selectin/CD62E One-Step ELISA Kit produced at Sunlong Medical™.