DESCRIPTION

Thrombopoietin (TPO) also known as megakaryocyte growth and development factor (MGDF), is a protein in human. The protein is a glycoprotein hormone produced by the liver and kidney, regulating the differentiation of megakaryocytes and platelets. While platelet and megakaryocyte concentrations have a negative feedback on TPO levels. It is also a humoral growth factor necessary for megakaryocyte proliferation and maturation, thrombopoiesis. TPO is the ligand for MLP/C_MPL, the product of myeloproliferative leukemia virus oncogene and one of the Class I hematopoietic cytokines. TPO promotes apoptosis of newly generated neurons in brain, an effect counteracted by Erythropoietin and neurotrophins.

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	1,277.1	53.0	4.2
2	8	241.2	6.7	2.8
3	8	125.3	4.4	3.5

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	1,257.6	73.7	5.9
2	16	239.8	6.2	2.6
3	16	125.0	3.6	2.9

RECOVERY

The recovery of human Thrombopoietin spiked to three different levels throughout the range of the assay in human serum was evaluated.

Sample Type		Average% of Expected	Range (%)
Human serum	1:2	100	96-105
	1:4	113	108-118

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.

		Human serum
1:2	Average% of Expected	100
	Range (%)	-
1:4	Average% of Expected	115
	Range (%)	111-120
1:8	Average% of Expected	109
	Range (%)	84-133
1:16	Average% of Expected	95
	Range (%)	76-113

CALIBRATION

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