**End-user must supply Sodium Barbital (C8H11N2NaO3)
Owren's Veronal Buffer
Catalog No.: DCP-OVB
Size:
500 mL
Sterile: Filtered 0.1-micron membrane TWICE, 0.04-micron membrane TWICE
Storage: 2-8°C
Shelf Life: 3 months
*Use before the expiry date given on the product label.
pH: 7.35 ± 0.02 (measured at 37°C)
Description:
A reagent fully compatible (not exclusive) with the Blood Coagulation Analyzer (Catalog No.: DCBio-SACA)
[Link]
AA historically validated, ready-to-use isotonic barbital (veronal) buffer solution containing 2.84 × 10
-² M (28.4 mM) sodium barbital in 1.25 × 10
-¹ M (125 mM) sodium chloride, adjusted to pH 7.35 ± 0.1. Originally formulated by Paul Arnor Owren in the 1950s and adopted universally across the hemostasis field, OVB is the reference-laboratory standard diluent for Clauss fibrinogen determinations, coagulation factor activity assays, and Owren-method prothrombin time testing. It provides a physiologically isotonic, pH-stable, non-chelating, non-interfering reaction vehicle that preserves fibrinogen structure and thrombin enzymatic activity during the critical plasma dilution and clot initiation steps. Compatible with all major automated and semi-automated coagulation analyzers.
Supplied as a ready-to-use liquid; no reconstitution required.
Sodium barbital (sodium diethylbarbiturate; the sodium salt of barbital) is the buffering species in OVB. Its selection reflects specific physicochemical advantages for hemostasis applications:
- pKa and working pH range: Barbital (free acid) has a pKa of approximately 7.4 at 25°C, placing its effective buffering range between pH 6.8 and 8.0. At the 2.84 × 10-² M working concentration, OVB maintains pH 7.35 ± 0.1 across the temperature range from refrigerator storage (2–8°C) to analyzer incubation temperature (37°C), providing stable pH throughout the pre-analytical and analytical workflow
- Ionic strength compatibility: Paired with 1.25 × 10-¹ M (125 mM) NaCl, the total ionic strength of OVB approximates that of diluted plasma, minimizing non-physiological charge effects on fibrinogen structure, thrombin–fibrinogen interaction kinetics, and calcium-dependent coagulation factor conformations..
- Non-chelating: Unlike citrate, EDTA, or oxalate, sodium barbital does not chelate calcium ions. This is critical for APTT-based factor assays that proceed through the calcium-dependent coagulation cascade — the buffer does not remove or compete for Ca²+ ions that are restored by the recalcification reagent.
- Enzymatic compatibility: At diagnostic working concentrations, barbital does not inhibit thrombin, Factor Xa, or any other serine protease involved in the coagulation cascade.
- Historical standardization: OVB has been the reference diluent for the Clauss fibrinogen method since Clauss's seminal 1957 publication and has been continuously validated across decades of automated coagulation analyzer development. WHO and NIBSC fibrinogen concentrate standards reference Owren-type isotonic barbital buffers in their reconstruction and assay protocols.
Composition:
| Ingredients |
| Sodium Barbital |
| Sodium Chloride |
| Ultrapure Water |
* All DiagnoCine Precision Sterile filtered-sterilized with 40 nanometer. Thus, mycoplasma contamination is prevented. The smallest size mycoplasma type can be about 0.2 microns.
* This product is manufactured under ISO 13485-certified and CE-approved facilities (Suppliers of DiagnoCine Precision). All final packaging, quality assurance, and testing are done at the DiagnoCine R&D and Quality Testing Center. All specific customization requests and assembly were accomplished at DiagnoCine Precision in Totowa, New Jersey, USA
