25-Hydroxy Vitamin D (25-OH-VD)

25-OH-VD Antibody

Name	25-Hydroxy Vitamin D (25-OH-VD) antibody
Platforms	Chemiluminescence immunoassay (CLIA), Immunochromatography assay (ICA), Turbidimetric Immunoassay (TIA)
Catalog #	K32w6	K31v3	K35c7
Usage	Detection
Epitopes	25-OH-VD2&3	25-OH-VD3 only	25-OH-VD2 only
Description	Mouse monoclonal antibody, cultured in vitro
Buffer	1×PBS，pH 7.4
Purity	Purity>98%, purified by Protein A/G chromatography
Storage	Aliquot and store at -20°C or lower. Avoid freeze / thaw cycles.

25-OH-VD Antigen

Name	25-Hydroxy Vitamin D (25-OH-VD) antigen
Description	Synthesized, C3 position BSA conjugated
Applications	Capture, detection, calibrator and quality control product
Catalog #	C1580
Purity	>90%, analyzed by R250-stained SDS-PAGE
Storage	Aliquot and store at -80°C. Avoid freeze / thaw cycles.
SDS-PAGE	Predicted MW 60-80kDa(tagged)

OEM Reagents

Name	Catalog #	Platform	Methodology
25-OH-VD Reagents	Q80h1	AE Chemiluminescence immunoassay	Sandwich
	Q60f1	AE Chemiluminescence immunoassay	Competitive
	Q70g1	ALP Chemiluminescence immunoassay	Competitive

Labeled & Conjugated antibody

Name	Catalog #	Platform	Methodology
AE labeled 25-OH-VD Antibody	L216u1	Chemiluminescence immunoassay	Sandwich
Biotin labeled 25-OH-VD Antibody	L217u1		Sandwich
AE labeled 25-OH-VD Antibody	L210u1		Competitive
ALP labeled 25-OH-VD Antibody	L212u1
Biotin labeled 25-OH-VD Antibody	L219u1

Miscellaneous

Name	Catalog #	Platform	Methodology
Dissociation Agent	D10a1	50μL /sample	AE/ALP Chemiluminescence

Product Information

Sandwich AE Chemiluminescence Immunoassay

Clinical comparative analysis: mass spectrum (MS) assigned

25-OH-VD sandwich antibodies of OKay Bio have been verified with a strong ability to recognize total 25-OH-VD. Okay^TM Biochemiluminescence sandwich immunoassay reagents (Q80h1) benchmarking industrial gold standard for detection: liquid chromatography-tandem mass spectrometry (LC-MS/MS). The detection result of Q80h1 is verified by the AE chemiluminescence platform with good coincidence upon the LC-MS/MS, and the correlation R² can reach 0.9153;customer verification results is up to 0.945.。

Figure 1. Clinical consistency (self tested)

Figure 2. Clinical consistency (customer tested）

Total 25-OH-VD recognition capacity

The cross-reactivity between 25-OH-VD antibody and 25-OH-VD2 directly affects the accuracy of total 25-OH-VD detection results. Validated by chemiluminescence platform, the 25-OH-VD sandwich antibody has good cross-reactivity with 25-OH-VD2 and 25-OH-VD3, and can effectively identify the total 25-OH-VD in the sample.

Concentration (ng/mL)	RLU
Concentration (ng/mL)	25-OH-VD2	25-OH-VD3
0	6986	5393
1	8838	6789
5	32207	28996
20	109482	93236
50	223470	198632
100	531087	423666

Figure 3. Recognition capacity of sandwich antibody to total 25-OH-VD

Table 1.Clinical comparative analysis data

Competitive ALP-AMPPD Chemiluminescence

Clinical comparative analysis: Abbott^TM assigned
K32w6 antibody was applied to detect Abbott^TM assigned serum samples (40 cases, concentration range: 5.9-81.4ng/mL), the coincidence rate of samples R²＞0.93。

Sample No.	Sample Concentration （ng/mL）	Detected Concentration （ng/mL）
1	5.9	4.88
2	6.9	6.54
3	9.8	6.79
...	...	...
39	68.6	65.12
40	81.4	73.84

Figure 4. Clinical coincidence rate of 25-OH-VD antibody in chemiluminescence platform

Table 2. Clinical comparative analysis data

Diagnostic Significance of Hydroxy Vitamin D (25-OH-VD)

Vitamin D (VD) is an essential substance for human health, growth and development. Its deficiency or excess is closely related to many diseases, such as musculoskeletal diseases, respiratory system diseases, cardiovascular disease, immune diseases, kidney diseases, neuropsychiatric diseases, etc.

Vitamin D is a steroid hormone that maintains the body's calcium balance by regulating intestinal absorption and renal reabsorption. There are two main types of vitamin D: vitamin D2 (VD2) and vitamin D3 (VD3). VD2 is mainly obtained from ingested food (accounting for about 10% of the total VD), and VD3 is mainly generated when the skin is irradiating with ultraviolet rays of the sun light. Internal vitamin D is transported to the liver via the blood after combining with albumin and VD-binding protein. Under the participation of 25-hydroxylase secreted by the liver, the 25-position of VD is hydroxylated to 25-(OH)-VD. In kidney, 25-(OH)-VD is further converted into biologically active 1, 25-(OH)2-VD3 (1, 25-dihydroxyvitamin D3, also known as calcitriol) under the action of 1α-hydroxylase. Finally, under the load of DBP transport protein, it reaches target organs such as small intestine and bone through the blood and binds to muclear receptor (VDRn) or membrane receptor (VDRm) to exert corresponding biological effects.

25-(OH)-VD is the main storage form of vitamin D in the body, accounting for more than 95% of the total VD. Due to its long half-life (2 to 3 weeks), not affected by blood calcium or thyroid, Therefore, 25-(OH)-VD has been recognized as the best indicator to objectively evaluate the VD content in the body.

Internal 25-OH-VD content (ng/mL)	Clinical Advice
< 10	Severely scarce
10-20	Scarce
20-30	Insufficient
30-100	Normal

References

[1] B. Oliveri, A.G. Diaz, M. Gonzalez Perna et al. Serum 25-OH-VD levels in adults living in the city of Buenos Aires: Importance of vitamin D supplementation[J]. Bone, 2016, 89:64.

[2] Adriana S. Dusso, Alex J. Brown, Eduardo Slatopolsky. Vitamin D[J] 2005, 289(1):F8-28.

[3] Lips, Paul, Graafmans, Wilco C. Vitamin D supplementation and fracture incidence in elderly persons[J] Annals of Internal Medicine, 1996, 124(4):400-406.