Parabar 10312 is a viscous cryoprotectant for both small and large molecule crystallography.1
Mildly air-unstable, small molecule compounds can be coated with Parabar under an inert atmosphere. The Parabar protected crystal sample can be cryocooled in a chilled nitrogen gas stream. Parabar has also been used successfully as a cryoprotectant for biological macromolecule crystals. Used during cryocrystallography to displace and reduce the amount of water (mother liquor, reagent) on the crystal after the crystal is mounted in a cryoloop. Coating the crystal with Parabar can minimize evaporation from the crystal and reduce exposure and slow diffusion of air (oxygen) to the crystal.
HR2-643 Parabar 10312 is no longer available and has been discontinued effective May 11, 2021.
HR2-862 Parabar 10312 is supplied as 5 ml in an amber glass vial with glass applicator rod in screw cap lid.
The viscosity of Parabar can be reduced to improve handling with fragile needle and blade crystals by mixing 50:50 with Paraffin Oil.
Parabar is a blend of polyisobutylenes with a Staudinger molecular weight of about 20,000 and contains about 20% polymer.
Refractive index 1.48487 at 20°C.
Kinematic viscosity 641 cSt at 100°C. Kinematic viscosity ratio 2.05 at 100°C.
Clear to slightly hazy is appearance.
Synonyms used in the crystallographic literature: Paratone® N, Paratone® 8277, Infineum V8512.
Paratone® is a registered trademark of Chevron Corporation.
5 mL bottle with applicator rod
1. H. Hope, Cryocrystallography of biological macromolecules: a generally applicable method. Acta Cryst. (1988) B44, 22-26.
2. Structure of the ligand-binding domain (LBD) of human androgen receptor in complex with a selective modulator LGD2226. F. Wang, X.- Liu, H. Li, K.- Liang, J. N. Miner, M. Hong, E. A. Kallel, A. van Oeveren, L. Zhi and T. Jiang. Acta Cryst. (2006). F62, 1067-1071.
3. H. Hope, Annu. Rev. Biophys. Chem. 1990 19:107-126.
4. S. Parkin and H. Hope, J. Appl. Cryst. (1998) pages 945-953.