Fractionation on the microscale of brain polyribosomes by electrophoresis on acrylamide gels

A method is described for brain polyribosome fractionation by acrylamide gel electrophoresis. Brain polyribosomes were run in 2.0% gels in quartz capillaries of 800 mum inner diameter where the gels were supported by capillary force. The gels could then be ultraviolet-scanned in situ. Amounts of brain polyribosomes as small as 10-10(-3) A260nm unit could be analysed by this method. The method was checked by running a macroscale-prepared brain polyribosome sample. The various electrophoretic bands obtained showed a favourable A260nm: A280 ratio. A short RNase treatment caused the disappearance of the slowly migrating bands and the emergence of a predominant band migrating faster than the dimer. The various polyribosomal bands were then identified by comparison with the mobility of polyribosome fractions taken from a sucrose gradient fractionation. Finally, the electrophoretic pattern of brain polyribosomes compared favourably with the pattern obtained by the classic method of sucrose gradient sedimentation. The electrophoretic fractionation of polyribosomes prepared from one rat hippocampus (80 mg) is presented.