History of analytical techniques used in structure determination Essay

History of analytical techniques used in structure determination - Essay Example The map tends to be fuzzy in some parts this is due to the problem of phasing loops but with the help of some software can usually predict up to 90% of the structure correctly and the remaining part is computed manually. The problem in this method is that it is very expensive and takes time and we can determine structure of only large crystal. The structural determination of protein is difficult by method because Crystallography requires purified protein in fairly large amount and it requires protein in form of a crystal and every protein can't be crystallized. This is due to the fact that forming the crystal required rather unusual conditions of pH and ionic strength. This method is also used to determine the structure of the components. This method is similar to X-ray diffraction but the main difference between these two methods is that it is done in the gas phase. In place of X-ray beam a beam of electrons is used in this method that scatter off the molecular electrons. Due to this large atoms scatter better than smaller ones. The main drawback or disadvantage of this method is that the compound must be volatile and maintain its structure in the gas phase. This method sometimes has lower accuracy because the compound is sometimes heated to put it in the gas phase. 3. Neutron Diffraction This method is also used to determine the structure of the crystal. This method is similar to X-ray crystallography except that a beam of neutrons is used in place of X-ray beam. This neutron beam scatters off the nuclei. The main advantage of using neutron beam is that all nuclei are of similar size and all can be found with comparable accuracy. This method is very useful when the location of hydrogen atoms is desired. Neutron diffraction generally gives more accurate bond lengths