12-ID-B routinely conducts simultaneous SAXS/WAXS measurements on biological macromolecules (protein, nucleic acids, complexes, etc) and other aqueous solution samples.
Experiment Details
Flow cells are used for room temperature (22°C) or varied temperature (4-90°C) measurements. Typical concentration for solution SAXS is in the range of 0.1-10 mg/ml and a higher concentration (>5mg/ml) is required for WAXS measurements.
Autosampler
A homemade autosampler is used for batch-mode, high throughput measurements, and can take 0.5ml tubes or/and 96-well plates.
Mail-in Service
Mail-in service of batch-mode measurements will be available in the early and late time period of each beamtime cycle. Interested users should contact the beamline staff at the beginning of the beamtime cycle for service availability.
Batch-Mode Requirements
Samples must be pure and stable. The volume of each sample / buffer is >=100 uL (140-160uL is easier for operation and recommended if having sufficient materials). To correct possible structure factor (influence of inter-particle interaction among molecules under study), three or more concentrations are recommended for each type sample/molecule, e.g., 1, 2, 4 mg/ml. Besides samples, matching buffers are also required for background measurements. To reduce the influence of possible beam drifting, measurements are done in the following order: one buffer, 3-4 samples, one buffer, 3-4 samples, ...
Inline FPLC SAXS
The beamline has a AKTA micro FPLC and can conduct inline FPLC SAXS for unstable protein or nucleic acid samples. Inline size exclusive chromatography SAXS (SEC-SAXS) is the most frequently used method. Users are welcome to bring their own columns or to use those we have available. AKTA micro is a versatile FPLC instrument and can run other liquid chromatographic methods besides size exclusion. Users who are interested in inline FPLC SAXS are recommended to contact the beamline staff.
Available SEC Columns
Superdex 75 Increase 5/150 GL, MW: 3-70KDa; bed volume: 3ml; typical running time: 20-30min
Superdex 75 Increase 10/300 GL, MW: 3-70KDa; bed volume: ~24ml; typical running time: 1-2hrs
Superdex 200 Increase 5/150 GL, MW: 10-600KDa; bed volume: 3ml; typical running time: 20-30min
Superdex 200 Increase 10/300 GL, MW: 10-600KDa; bed volume: ~24ml; typical running time: 1-2hrs
Superose 6 Increase 10/300 GL, MW: 5-5000KDa; bed volume: ~24ml; typical running time: 1-2hrs