| 25-OH-VD

In hepatocytes (liver cells), vitamin D is hydroxylated to form 25-hydroxyvitamin D (calcidiol; calcifediol). Exposure to sunlight or dietary intake of vitamin D increases serum concentrations of 25-hydroxyvitamin D. 25-Hydroxyvitamin D constitutes the major circulating form of vitamin D, and the sum of 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 concentrations in serum is used as an indicator of vitamin D nutritional status.
 

| 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)	200	100	50	25	12.5	6.25	3.12	0
OD	0.188	0.27	0.389	0.642	0.929	1.38	1.766	1.842

 

| Repeatability

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

| Recovery

The recovery of Human 25-OH-VD 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)	81-101	96
Plasma(n=8)	92-105	101
Cell Culture Supernates(n=8)	97-108	105

 

| Linearity

Samples were spiked with high concentrations of Human 25-OH-VD 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 (%)	83-95	88-96	90-110
	Average (%)	91	93	96
1 : 4	Range (%)	89-104	87-108	105-115
	Average (%)	93	98	110