Storage Conditions: 4-20 C
pH: Varies
Conductance: Varies
Appearance: Clear Solutions
Features:
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96 Individual Crystallization Conditions
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Ultra Pure PEGs - USP Grade
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Polydisperse PEG Cocktail - 5 PEGs in each condition
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pH measured and recorded for both the stock buffers and final crystallization conditions
The PurePEGs Crystallization Screen features conditions that each contain a mixture of purified polyethylene glycols, ranging from 300 MW to 8000 MW. At a total concentration of 22.5% PEG combined with various salts and buffers, the conditions are designed to span a wide cross section of PEG crystallization space.
Many successful crystallization conditions comprise combinations of PEGs and salts adjusted to a particular pH. However, the necessity to sample a broad range of PEG precipitants during initial sparse matrix screening renders comprehensive PEG screening at this stage highly challenging. Interestingly, there is evidence to suggest that protein concentration conditions identified using a particular PEG can be repeated when using mixtures of PEGs as a single precipitant. Consequently, a more rational screening strategy should be to use mixtures of PEGs rather than conditions containing individual PEGs. In Vapor Diffusion experiments, this approach significantly minimizes the number of conditions to be sampled and the volume of protein necessary to explore PEG crystallization space.
Citations:
- J. Newman et al. Acta Crystallogr D. 61, 1426 (2005)
- R. Page et al. Acta Crystallog D. 59, 1028 (2003)
- J.W. Wooh et al. Acta Crystallog D. 59, 769 (2003)
- J.T. Bukrinsky et al. J Appl Cryst. 34, 533 (2001)
PurePEGs Information Sheet (
PDF)
Please note: As of April, 2018, the salt in condition #15 (B3) was changed from 0.3 Cadmium Sulfate to 0.2 Cadmium sulfate.
Formulations from April, 2018:
- PurePEGs Formulations (PDF), (XLS)
Formulations prior to April, 2018:
- PurePEGs Formulations (PDF), (XLS)