DESCRIPTION

CXC motif chemokine ligand 1 (CXCL1), a CXC chemokine, is also known as growth-regulated (or-related) oncogene-α (Gro-α) and melanoma growth-stimulatory activity (MGSA). It is one of seven chemokines that activate the CXC motif chemokine receptor 2 (CXCR2) and one of the most studied CXC chemokines. CXCL1 is a chemoattractant cytokine. Its most important property is to cause chemotaxis of immune cells, mainly neutrophils, and to a lesser extent CD14+ monocytes and basophils, but not T cells. It also reduces neutrophil apoptosis and thus increases the accumulation of these cells at sites of inflammatory reactions. CXCL1 also causes the chemotaxis of endothelial cells and thus participates in angiogenesis.

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	518.8	7.3	1.4
2	8	132.2	3.7	2.8
3	8	64.3	1.3	2.0

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	543.7	26.5	4.9
2	16	134.9	4.2	3.1
3	16	67.3	3.6	5.3

RECOVERY

The recovery of mouse CXCL1 spiked to three different levels throughout the range of the assay in various matrices was evaluated.

Sample Type		Average% of Expected	Range (%)
Mouse serum	1:4	109	98-120
	1:8	97	93-99
Cell culture supernatant	1:32	113	111-114

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 cell culture supernatant samples were initially diluted 1:2.)

		Mouse serum	Cell culture supernatant
1:2	Average% of Expected	100	100
	Range (%)	-	-
1:4	Average% of Expected	103	87
	Range (%)	100-106	86-89
1:8	Average% of Expected	96	81
	Range (%)	93-99	78-83
1:16	Average% of Expected	96	75
	Range (%)	94-99	74-76

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant mouse CXCL1 produced at Sunlong Medical™.