DESCRIPTION

Vitamin D BP belongs to the albumin family and it is a multifunctional protein found in plasma, ascitic fluid, cerebrospinal fluid and on the surface of many cell types. It is expressed in the liver. And it is involved in vitamin D transport and storage, scavenges of extracellular G-actin, and enhances of the chemotactic activity of C5 alpha for neutrophils in inflammation and macrophage activation. The presence of genetic variants in the Vitamin D BP gene are related to certain diseases, mostly concerning cancers (breast, prostate, pancreatic, lung, colorectal, basal cell carcinoma cancer and cutaneous melanoma) or other related diseases (thyroid autoimmunity disorders, obesity, diabetes mellitus, bone metabolism, rheumatoid arthritis, ankylosing spondylitis, asthma, chronic obstructive pulmonary disease, tuberculosis and coronary artery diseases).

PRINCIPLE OF THE ASSAY

Sandwich ELISA structure (Detection antibody labeled with biotin) A capture antibody is pre-coated onto the bottom of wells which binds to analyte of interest. A detection antibody labeled with biotin also binds to the analyte. Streptavidin-HRP binds to the biotin. TMB acts as the HRP substrate and the solution color will change from colorless to blue. A stop solution containing sulfuric acid turns 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 20 times on one plate to assess intra-assay precision. Inter-assay Precision (Precision between assays) Three samples of known concentration were tested in 24 separate assays to assess inter-assay precision.

Intra-assay Precision

Sample	n	Mean (ng/mL)	SD	CV%
1	20	4.04	0.11	2.85
2	20	1.02	0.03	2.88
3	20	0.27	0.01	5.46

Inter-assay Precision

Sample	n	Mean (ng/mL)	SD	CV%
1	24	3.84	0.14	3.67
2	24	0.99	0.02	2.05
3	24	0.26	0.02	6.49

RECOVERY

The recovery of human Vitamin D BP spiked to three different levels throughout the range of the assay in various matrices was evaluated. (The human serum was initially diluted 1:40,000, the urine was initially diluted 1:4)

Sample Type		Average% of Expected	Range (%)
Human serum	1:2	99	85-112
	1:4	100	90-109
Urine	1:2	75	71-81
	1:4	74	72-78

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 human serum was initially diluted 1:20,000, the urine was initially diluted 1:2)

		Human serum	Urine
1:2	Average% of Expected	100	100
	Range (%)	-	-
1:4	Average% of Expected	94	102
	Range (%)	78-109	90-116
1:8	Average% of Expected	92	95
	Range (%)	84-103	77-122

CALIBRATION

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

Ordering & shipping

• Minimum order: 1 kit
• Lead time: varies with order quantity and specifications. Please consult your local distributor or our sales team for confirmation
• Payment: T/T 100% in advance; PayPal; Alibaba Trade Assurance
• Shipping: FedEx / DHL / UPS express; cold-chain packing available on request
• Price: USD, per kit (48T / 96T options available)