DESCRIPTION

Signaling lymphocytic activation molecule 3 (SLAMF3), also known as CD229 or Ly9, is a type I transmembrane glycoprotein that belongs to the SLAM family receptors. It is composed of an extracellular region, which consists of four Ig-like domains, a transmembrane region, and a cytoplasmic tail, which includes two immunoreceptor tyrosine-based signaling motifs (ITSMs) and other tyrosine residues that act as binding sites for the SH2 structural domains. SLAMF3 is mainly expressed in immune cells, such as T, B, and natural killer cells, and it is involved in the fundamental activation and suppression of these immune cells, as well as the regulation of complex immune networks.

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	1,220.1	21.4	1.8
2	8	332.9	5.0	1.5
3	8	175.4	2.4	1.4

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	1,235.0	22.7	1.8
2	16	335.8	5.4	1.6
3	16	178.9	4.6	2.6

RECOVERY

The recovery of human CD229/SLAMF3 spiked to three different levels throughout the range of the assay in cell lysate was evaluated.

Sample Type		Average% of Expected	Range (%)
Cell lysate	1:32	91	82-108
	1:64	86	85-88

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 1:32.)

		Cell lysate
1:2	Average% of Expected	100
	Range (%)	-
1:4	Average% of Expected	103
	Range (%)	102-104
1:8	Average% of Expected	108
	Range (%)	107-109
1:16	Average% of Expected	116
	Range (%)	114-117

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human Human CD229/SLAMF3 One-Step ELISA Kit produced at Sunlong Medical™.