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Robbins Scientific Tango liquid handling systems and photomicrographic reader tables.
The high-throughput
crystallization laboratory at HWI houses state-of-the-art facilities
for screening
conditions suitable to grow the high quality single crystals required
for molecular structure determination by X-ray diffraction. As
currently
configured, the lab has the capacity to evaluate as many as 200 new
samples each month. A large number of experiments (1536) can be
set up within
minutes after a protein sample is received, thereby reducing the
chance for degradation.
The approach used for screening growth conditions is to incubate, under paraffin oil, small aqueous aliquots of the sample protein with chemical mixtures (called ‘cocktails’) that are designed to induce a state of supersaturation. The protein molecules will then be driven out of solution and, under proper conditions, crystals will form. In the high-throughput lab, screening experiments are conducted in 1536-well microassay plates using 1536 distinct cocktails containing varying concentrations of salts and other precipitants in buffers spanning a pH range from 4.5 to 10.5.
The high-throughput experiments are set up using Robbins Scientific Tango pipetting robots.Two custom-made, photomicrographic reader tables that can accommodate as many as 28 crystallization plates each, are used to document the results with a digital camera. Digital images are transferred over a gigabit switched network to a 1 TB disc storage array with failover systems. The plates are stored in temperature-controlled incubators.
The crystallization lab also contains all the equipment needed to optimize crystal size and quality once the initial conditions have been found. The instruments available for preparing and characterizing macromolecular solutions and crystallization cocktails include pH meters, electronic balances, centrifuges, refractometers, a spectrophotometer, a viscometer, and an osmometer. Two DynaPro temperature-controlled dynamic light scattering instruments are available to make measurements of solution homogeneity. These measurements are useful for predicting the likelihood that crystals will form from a solution.
The approach used for screening growth conditions is to incubate, under paraffin oil, small aqueous aliquots of the sample protein with chemical mixtures (called ‘cocktails’) that are designed to induce a state of supersaturation. The protein molecules will then be driven out of solution and, under proper conditions, crystals will form. In the high-throughput lab, screening experiments are conducted in 1536-well microassay plates using 1536 distinct cocktails containing varying concentrations of salts and other precipitants in buffers spanning a pH range from 4.5 to 10.5.
The high-throughput experiments are set up using Robbins Scientific Tango pipetting robots.Two custom-made, photomicrographic reader tables that can accommodate as many as 28 crystallization plates each, are used to document the results with a digital camera. Digital images are transferred over a gigabit switched network to a 1 TB disc storage array with failover systems. The plates are stored in temperature-controlled incubators.
The crystallization lab also contains all the equipment needed to optimize crystal size and quality once the initial conditions have been found. The instruments available for preparing and characterizing macromolecular solutions and crystallization cocktails include pH meters, electronic balances, centrifuges, refractometers, a spectrophotometer, a viscometer, and an osmometer. Two DynaPro temperature-controlled dynamic light scattering instruments are available to make measurements of solution homogeneity. These measurements are useful for predicting the likelihood that crystals will form from a solution.