DESCRIPTION

Peptidoglycan recognition protein 1 (PGLYRP1, also known as PGRP-S) belongs to a family of evolutionarily conserved innate immunity proteins, which in mammals also include PGLYRP2, PGLYRP3, and PGLYRP4. PGLYRP1 is highly expressed in polymorphonuclear leukocytes and to a lower extent in many non-immune cells. It recognizes bacterial peptidoglycan and functions in antibacterial immunity and inflammation. Additionally, PGLYRP1 has been identified as a ligand for TREM-1.

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	1,309.4	36.2	2.8
2	8	329.1	10.6	3.2
3	8	162.6	5.1	3.1

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	1,288.9	33.7	2.6
2	16	316.8	31.9	10.1
3	16	158.4	6.4	4.0

RECOVERY

The recovery of human PGLYRP1 spiked to three different levels throughout the range of the assay in various matrices was evaluated.

Sample Type		Average% of Expected	Range (%)
Human serum	1:80	107	99-115
	1:160	106	101-113
Saliva	1:40	93	84-107
	1:80	87	82-93

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 serum and saliva was initially diluted 1:10.)

		Human serum(Sample Diluent PT 4B1)	Saliva(Sample Diluent PT 4)
1:2	Average% of Expected	100	100
	Range (%)	-	-
1:4	Average% of Expected	107	103
	Range (%)	104-110	99-107
1:8	Average% of Expected	109	101
	Range (%)	107-111	86-117
1:16	Average% of Expected	114	109
	Range (%)	112-115	97-121

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human PGLYRP1 produced at Sunlong Medical™.