JBScreen Classic 6 (Ammonium Sulfate 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 0.5 M Ammonium Sulfate, 1.0 M Li Sulfate, 0.1M Na Citrate
A2 1.0 M Ammonium Sulfate
A3 1.0 M Ammonium Sulfate, 0.1 M Na Acetate pH 4.6
A4 1.0 M Ammonium Sulfate, 2% PEG 400, 0.1 M Na HEPES pH 7.5
A5 1.0 M Ammonium Sulfate, 0.1 M TRIS HCl pH 8.5
A6 1.2 M Ammonium Sulfate, 3% iso-Propanol, 0.05 M Na Citrate
B1 1.5 M Ammonium Sulfate, 15% Glycerol, 0.1 M TRIS HCl pH 8.5
B2 1.6 M Ammonium Sulfate, 0.5 M Li Chloride
B3 1.6 M Ammonium Sulfate, 1.0 M Li Sulfate
B4 1.6 M Ammonium Sulfate, 0.1 M Na HEPES pH 7.5, 0.2 M Na Chloride
B5 1.6 M Ammonium Sulfate, 2% PEG 1000, 0.1 M Na HEPES pH 7.5
B6 1.8 M Ammonium Sulfate, 0.1 M Na MES pH 6.5
C1 2.0 M Ammonium Sulfate, 2 M Na Chloride
C2 2.0 M Ammonium Sulfate, 0.1 M Na Acetate pH 4.6
C3 2.0 M Ammonium Sulfate, 5% PEG 400, 0.1 M Na MES pH 6.5
C4 2.0 M Ammonium Sulfate, 0.1 M TRIS HCl pH 8.5
C5 2.2 M Ammonium Sulfate
C6 2.2 M Ammonium Sulfate, 20% Glycerol
D1 2.4 M Ammonium Sulfate, 0.1 M Na Citrate
D2 3.0 M Ammonium Sulfate, 1% MPD
D3 3.0 M Ammonium Sulfate, 10% Glycerol
D4 3.5 M Ammonium Sulfate, 0.1 M Na HEPES pH 7.5
D5 3.5 M Ammonium Sulfate, 1% MPD, 0.1 M Na MES pH 6.5
D6 3.5 M Ammonium Sulfate

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.