DESCRIPTION

Matrix metalloproteinase-7 (MMP-7)/ matrilysin is a member of the MMP family, but is structurally different from the other MMPs by virtue of the absence of a conserved COOH-terminal protein domain. MMPs are involved in the breakdown of extracellular matrix in normal physiological processes, such as embryonic development reproduction, and tissue remodeling, as well as in disease processes, such as arthritis and cancer metastasis. Most MMP's are secreted as inactive proproteins which are activated when cleaved by extracellular proteinases. MMP-7 degrades proteoglycans, fibronectin, elastin and casein, and is involved in wound healing, tumor progression, pulmonary fibrosis, and development of choroidal neovascularization in age-related macular degeneration. The expression of MMP-7 is increased in most tumors.

PRINCIPLE OF THE ASSAY

Sandwich ELISA structure (Detection antibody labeled with biotin) A capture antibody is pre-coated onto the bottom of wells which binds to analyte of interest. A detection antibody labeled with biotin also binds to the analyte. Streptavidin-HRP binds to the biotin. TMB acts as the HRP substrate and the solution color will change from colorless to blue. A stop solution containing sulfuric acid turns 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 20 times on one plate to assess intra-assay precision. Inter-assay Precision (Precision between assays) Three samples of known concentration were tested in 24 separate assays to assess inter-assay precision.

Intra-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	20	1,731.7	107.1	6.2
2	20	380.7	12.9	3.4
3	20	100.5	6.9	6.9

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	24	1,921.6	206.0	10.7
2	24	432.9	36.0	8.5
3	24	104.8	9.8	9.3

RECOVERY

The recovery of human Total MMP-7 spiked to three different levels throughout the range of the assay in various matrices was evaluated.

Sample Type		Average% of Expected	Range (%)
Human serum	1:15	87	75-119
	1:30	94	77-119
saliva	1:50	97	75-124
	1:100	106	84-125
urine	1:75	102	78-128
	1:150	100	83-129

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 samples were initially diluted 1:2. The saliva samples were initially diluted 1:20. The urine samples were initially diluted 1:10.)

		Human serum(Sample Diluent PT 4)	Saliva(Sample Diluent PT 4)	Urine(Sample Diluent PT 4-tf)
1:2	Average% of Expected	100	100	100
	Range (%)	-	-	-
1:4	Average% of Expected	105	83	101
	Range (%)	88-123	78-89	96-106
1:8	Average% of Expected	100	84	97
	Range (%)	91-114	81-86	71-112
1:16	Average% of Expected	105	74	102
	Range (%)	94-116	70-78	78-115

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human Total MMP-7 produced at Sunlong Medical™.