JBScreen Classic 5 (PEG 8000 to 20000 based)

The JBScreen Crystal Screening Kits 1-10 cover 240 of the most prominent buffers for protein crystallization. Their compositions result from data mining of several thousands of crystallized proteins. JBScreen represents the statistically most successful buffers that yielded protein crystals suitable for X-ray diffraction. The JBScreen buffers are principally ordered by type and concentration of the precipitant. This allows easy extraction of all relevant information and is already a first step to a refinement: Once you get a hit, you immediately see the effects of the neighbouring conditions. Subsequent fine tuning of preliminary hits will be much more efficient. Apart from saving you the tedious pipetting, sterile packed aliquots have several other important advantages: While common bulk solutions are frequently contaminated by the time you use the first aliquot, JBScreen is alalways fresh and sterile. Evaporation of solvent (with the resulting change of the buffer) just won’t happen – you will get extremely reproducible screening results.

The kit contains the following buffers:
A1 12% PEG 8000, 5% Glycerol, 0.1 M K Chloride
A2 12% PEG 8000, 10% Glycerol, 0.5 M K Chloride
A3 15% PEG 8000, 0.2 M Ammonium Sulfate
A4 15% PEG 8000, 0.5 M Li Sulfate
A5 15% PEG 8000, 0.1 M Na MES pH 6.5, 0.2 M Na Acetate
A6 15% PEG 8000, 0.05 M Ammonium Sulfate, 0.1 M Na Citrate
B1 18% PEG 8000, 0.1 M Na HEPES pH 7.5, 0.2 M Ca Acetate
B2 18% PEG 8000, 2% iso-Propanol, 0.1 M Na HEPES pH 7.5, 0.1 M Na Acetate
B3 18% PEG 8000, 0.1 M TRIS HCl pH 8.5, 0.2 M Li Sulfate
B4 20% PEG 8000, 0.1 M Na HEPES pH 7.5
B5 20% PEG 8000, 0.1 M Na MES pH 6.5, 0.2 M Mg Acetate
B6 20% PEG 8000, 0.1 M CHES pH 9.5
C1 22% PEG 8000, 0.1 M Na MES pH 6.5, 0.2 M Ammonium Sulfate
C2 25% PEG 8000, 0.2 M Li Chloride
C3 30% PEG 8000, 0.2 M Ammonium Sulfate
C4 8% PEG 10000, 0.1 M Na Acetate pH 4.6
C5 14% PEG 10000, 0.1 M Imidazole HCl pH 8.0
C6 16% PEG 10000, 0.1 M TRIS HCl pH 8.5
D1 18% PEG 10000, 20% Glycerol, 0.1 M TRIS HCl pH 8.5, 0.1 M Na Chloride
D2 20% PEG 10000, 0.1 M Na HEPES pH 7.5
D3 30% PEG 10000, 0.1 M TRIS HCl pH 8.5
D4 10% PEG 20000, 0.1 M Na MES pH 6.5
D5 17% PEG 20000, 0.1 M TRIS HCl pH 8.5, 0.1 M Mg Chloride
D6 20% PEG 20000

Buffer preparation:
• Chemicals used were of MicroSelect grade for Molecular Biology.
• Buffers were prepared as 1 M stock solutions. The pH was adjusted with HCl (Imidazole, TRIS), NaOH (Bicine, CHES, HEPES, MES), Citric Acid (Citrate) or Acetic Acid (Acetate) (23°C; Fisher pH electrode).
• Percentages given are always w/v values (for solids as well as for liquids).
• The final volume was adjusted with >18 MOhm water.
• Solutions were filtered (0.2 µm) and filled in ampoules/tubes under sterile conditions.