DESCRIPTION

CSF1R (colony-stimulating factor 1 receptor) belongs to the type III protein tyrosine kinase receptor family. CSF1R is ubiquitously expressed in macrophages, microglia, osteoclasts, and myeloid dendritic cells, but is rarely expressed in hematopoietic stem cells.CSF1R-mediated signaling is crucial for the differentiation and survival of the mononuclear phagocyte system and macrophages in particular.

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	1,482.4	27.6	1.9
2	8	393.5	6.4	1.6
3	8	111.1	3.0	2.7

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	1,481.8	24.4	1.6
2	16	396.2	18.1	4.6
3	16	111.2	3.1	2.8

RECOVERY

The recovery of human CSF1R/CD115 spiked to three different levels throughout the range of the assay in various matrices was evaluated.

Sample Type		Average% of Expected	Range (%)
Human plasma	1:3,200	99	86-116
Cell lysate	1:16	95	79-120

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 1:200. The cell lysate was initially diluted 1:4.)

		Human plasma	Cell lysate
1:2	Average% of Expected	100	100
	Range (%)	-	-
1:4	Average% of Expected	110	110
	Range (%)	107-112	109-111
1:8	Average% of Expected	120	97
	Range (%)	117-123	94-99
1:16	Average% of Expected	116	116
	Range (%)	102-129	109-122

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human Human CSF1R/CD115 One-Step ELISA Kit produced at Sunlong Medical™.