JBScreen Classic 9 (Alcohol/Salt 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 5% iso-Propanol, 0.1 M Na HEPES pH 7.5
A2 10% iso-Propanol, 0.1 M Na Acetate pH 4.6, 0.2 M Ca Chloride
A3 10% iso-Propanol, 0.1 M Na HEPES pH 7.5, 0.2 M Na Citrate
A4 10% iso-Propanol, 0.1 M TRIS HCl pH 8.5, 0.01 M Mg Chloride
A5 12% iso-Propanol, 0.1 M TRIS HCl pH 8.5, 0.05 Na Chloride
A6 15% iso-Propanol, 0.1 M Na MES pH 6.5, 0.2 M Na Citrate
B1 15% iso-Propanol, 0.1 M Na HEPES pH 7.5, 0.2 M Na Citrate
B2 15% iso-Propanol, 0.1 M Na HEPES pH 7.5, 0.2 M Mg Chloride
B3 15% iso-Propanol, 0.1 M TRIS HCl pH 8.5, 0.2 M Ammonium Acetate
B4 20% iso-Propanol, 0.1 M Na Acetate pH 4.6, 0.2 M Ca Chloride
B5 20% iso-Propanol, 0.1 M Na HEPES pH 7.5, 0.2 M Na Citrate
B6 25% iso-Propanol, 0.1 M Na HEPES pH 7.5, 0.1 M Mg Chloride
C1 30% iso-Propanol, 0.1 M Na MES pH 6.5, 0.2 M Na Citrate
C2 30% iso-Propanol, 0.1 M Na HEPES pH 7.5, 0.2 M Mg Chloride
C3 30% iso-Propanol, 0.1 M TRIS HCl pH 8.5, 0.2 M Ammonium Acetate
C4 25% tert.-Butanol, 0.1 M TRIS HCl pH 8.5, 0.1 M Ca Chloride
C5 35% tert.-Butanol, 0.1 M Na Citrate pH 5.6
C6 0.2 M Ammonium Dihydrogen Phosphate
D1 0.2 M K,Na Tartrate
D2 0.2 M Mg Acetate
D3 0.4 M Ammonium Dihydrogen Phosphate
D4 0.4 M K,Na Tartrate
D5 0.4 M K,Na Tartrate, 0.1 M TRIS HCl pH 8.5
D6 0.5 M Ammonium Dihydrogen Phosphate, 0.2 M Na Citrate

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.