The PurePEGs screen comprises 96 conditions for each of which the precipitant is a smear of purified PEGs, ranging from 300 to 8000 in molecular weight.
- 96 individual crystallization conditions
- Ultra pure PEGs - USP grade
- Polydisperse PEG cocktail – 5 PEGs ranging from 300 to 8000 in each condition
- Effective forvapor diffusion, but optimized for the Crystal Former
- Highest control of manufacturing impurities in the PEGs
- Available as tube or deep-well block formats
Many of the most successful crystallization conditions are a combination of PEG and salts adjusted to a particular pH. However, in an initial sparse matrix screen, sample the vast space of different salts versus different molecular weight PEGs, at a range of pH, is a challenging prospect. There is evidence to suggest that protein crystallization hits obtained using a particular PEG can be repeated when using alternative PEGS or mixtures of PEGs. Consequently, a more rational screening strategy should use mixtures of PEG rather than individual components.
Why use USP grade PEGs?
Additionally, the pH of various sparse matrix screen solutions has been observed to significantly differ from what can be inferred from the precipitant composition. Since most crystallization screens are manufactured by simply adding individual pre-formulated components to generate a final solution, without adjusting or measuring the pH of the final solution, there are bound to be significant discrepancies between the expected and actual pH of the precipitant condition. Particularly for conditions containing technical grade PEG, variable concentrations of sodium sulfate, sodium hydroxide or sulfuric acid, will affect the pH and the sales in the final solution. As a consequence, protein crystallographers trying to optimize a crystallization hit from such a condition may have an incorrect starting point for their efforts.
To address these issues, the PurePEGs screen contains USP grade, highly purified PEG components.
Can I use these in vapor diffusion trials?
Yes! The PurePEGs screen has been formulated for use in both liquid-liquid diffusion and vapor diffusion. For the latter, the use of a PEG cocktail, or smear, as the precipitating reagent permits reduction in the number of PEG-based conditions needed to identify an initial crystallization hit. In the former, the cocktail permits the exploration of broad and complex PEG-based gradients along the Crystal Former capillary.
50% PurePEGs Cocktail - 100 mL
Optimize your crystals from the PurePEGs crystallization screen with the PurePEGs cocktail. This... Read more
PurePEGs-96 Crystallization Screen Deep Well Block
The PurePEGs-96 Crystallization Screen features conditions that each... Read more
|PurePEGSs-96 Crystallization Screen 10 mL format The PurePEGs-96 Crystallization Screen features conditions that each contain a mixture of purified... Read more||PP96-10mL||$750.00|
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