| 摘要 |
PURPOSE:To prepare a large single crystal having small content of defect by forming once amorphous precipitate from solution of a protein or nucleic acid to form thus crystal nuclei, then eliminating the amorphous precipitate leaving the crystal nuclei alone, and achieving the growth of the nuclei thereafter. CONSTITUTION:The protein (e.g. myoglobin) or nucleic acid (e.g. transfer RNA) is dissolved in a liquid solvent. Then, the soln. is heated or cooled temporarily under conditions near the saturated point to form the amorphous precipitate and crystal nuclei of the protein or nucleic acid. Then, the temp. is brought back to the original temp. eliminating the amorphous precipitate by dissolution leaving the crystal nuclei having low solubility alone and allowing remaining the crystal nuclei to grow under mild condition, to obtain thus a single crystal of the protein or nucleic acid. Since the number of the crystal nuclei is restricted by this method, the large single crystal is obtd., and the formation of a twin crystal is retarded. Thus, the single crystal having good quality is obtd.
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