DESCRIPTION

Tissue factor (TF),also named coagulation factor III or F3, is a transmembrane protein that functions as a high-affinity receptor for factor (F)VII and FVIIa. The TF-FVIIa complex is the primary initiator of blood coagulation and plays an essential role in hemostasis. TF is expressed on perivascular cells and epithelial cells at organ and body surfaces where it forms a hemostatic barrier. TF also provides additional hemostatic protection to vital organs, such as the brain, lung, and heart. Under pathological conditions, TF can trigger both arterial and venous thrombosis.

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	258.0	4.3	1.7
2	8	65.0	0.9	1.4
3	8	30.5	1.5	4.9

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	254.5	5.2	2.0
2	16	62.9	2.5	4.0
3	16	29.3	1.8	6.1

RECOVERY

The recovery of human Coagulation Factor III/Tissue Factor spiked to three different levels throughout the range of the assay in various matrices was evaluated.

Sample Type		Average% of Expected	Range (%)
Human plasma	1:4	109	101-115
Urine	1:4	116	112-120
Cell lysate	1:400	109	101-121

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 1:25.)

		Human plasma(Sample Diluent PT 3-ef)	Urine(Sample Diluent PT 4B1)	Cell lysate(Sample Diluent PT 4B1)
1:2	Average% of Expected	100	100	100
	Range (%)	-	-	-
1:4	Average% of Expected	116	104	104
	Range (%)	104-128	93-115	89-119
1:8	Average% of Expected	115	96	105
	Range (%)	110-121	77-115	85-125
1:16	Average% of Expected	120	102	96
	Range (%)	120-121	87-116	80-111

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human Coagulation Factor III/Tissue Factor produced at Sunlong Medical™.