| FXR

The bile acid receptor (BAR), also known as farnesoid X receptor (FXR) or NR1H4 (nuclear receptor subfamily 1, group H, member 4), is a nuclear receptor that is encoded by the NR1H4 gene. FXR is expressed at high levels in the liver and intestine. Chenodeoxycholic acid and other bile acids are natural ligands for FXR. Similar to other nuclear receptors, when activated, FXR translocates to the cell nucleus, forms a dimer (in this case a heterodimer with RXR) and binds to hormone response elements on DNA, which up- or down-regulates the expression of certain genes.
 

| 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 (ng/mL)	10	5	2.5	1.25	0.625	0.312	0.156	0
OD	2.24	1.55	0.98	0.52	0.32	0.21	0.17	0.08
Corrected OD	2.16	1.47	0.9	0.44	0.24	0.13	0.09	-

 

| Repeatability

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

| Recovery

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

 

Sample Type	Range(%)	Average Recovery(%)
Tissue Homogenates(n=8)	92-105	102
Cell Lysates(n=8)	96-108	105

 

| Linearity

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

 

		Tissue Homogenates(n=4)	Cell Lysates(n=4)
1 : 2	Range (%)	84-95	90-110
	Average (%)	90	96
1 : 4	Range (%)	89-103	105-114
	Average (%)	94	108