DESCRIPTION

Sialomucins are a heterogeneous group of secreted or membrane-associated mucins that appear to play two key but opposing roles in vivo: first as cytoprotective or antiadhesive agents, and second as adhesion receptors. CD164 is a type I integral transmembrane sialomucin that functions as an adhesion receptor. It is known to function as a receptor that regulates stem cell localization to the bone marrow. Important role of CD164 in prostate cancer metastasis, promoting myogenesis and regulating myoblast migration so far been revealed.

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	2,590.4	61.1	2.4
2	8	644.2	9.5	1.5
3	8	318.4	10.1	3.2

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	2,636.2	72.4	2.7
2	16	646.3	13.3	2.1
3	16	316.6	13.2	4.2

RECOVERY

The recovery of human CD164 spiked to three different levels throughout the range of the assay in various matrices was evaluated.

Sample Type		Average% of Expected	Range (%)
Human plasma	1:16	82	76-88
Cell lysate	1:256	95	85-108

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 lysate was initially diluted 1:64.)

		Human plasma	Cell lysate
1:2	Average% of Expected	100	100
	Range (%)	-	-
1:4	Average% of Expected	125	89
	Range (%)	120-131	85-94
1:8	Average% of Expected	124	79
	Range (%)	123-125	70-88
1:16	Average% of Expected	92	80
	Range (%)	91-94	79-82

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human CD164 produced at Sunlong Medical™.