| PAPP-A

Pappalysin-1, also known as pregnancy-associated plasma protein A, and insulin-like growth factor binding protein-4 protease is a protein encoded by the PAPPA gene.PAPPA is a secreted protease whose main substrate is insulin-like growth factor binding proteins. Pappalysin-1 is also used in screening tests for Down syndrome. PAPPA is a secreted metalloproteinase which cleaves insulin-like growth factor binding proteins (IGFBPs). PAPPA's proteolytic function is activated upon collagen binding. It is thought to be involved in local proliferative processes such as wound healing and bone remodeling. Low plasma level of this protein has been suggested as a biochemical marker for pregnancies with aneuploid fetuses (fetuses with an abnormal number of chromosomes).
 

| Typical data

As the OD values of the standard curve may vary according to the conditions of the actual assay performance (e.g. operator, pipetting technique, wash technique or temperature effects), the operator should establish a standard curve for each test. Typical standard curve and data are provided below for reference only.

 

Concentration (pg/mL)	1000	500	250	125	62.5	31.2	15.6	0
OD	0.19	0.24	0.31	0.55	0.97	1.38	1.96	2.52

 

| Repeatability

Intra-assay Precision (Precision within an assay)：CV% < 10%; Inter-assay Precision (Precision between assays)：CV% < 10%
 

| Recovery

The recovery of Human PAPP-A spiked at three different levels in samples throughout the range of the assay was evaluated in various matrices.

 

Sample Type	Range(%)	Average Recovery(%)
Serum(n=8)	84-101	96
Plasma(n=8)	92-105	102
Cell Culture Supernates(n=8)	96-108	105

 

| Linearity

Samples were spiked with high concentrations of Human PAPP-A and diluted with Universal Diluent to produce samples with values within the range of the assay.

 

		Serum(n=4)	Plasma(n=4)	Cell Culture Supernates(n=4)
1 : 2	Range (%)	84-95	88-96	90-110
	Average (%)	90	93	96
1 : 4	Range (%)	89-103	87-108	105-115
	Average (%)	94	98	108