Abstract
Abnormal and normal blood smears were examined with an electron microprobe for their metallic Zn and Ti content in an attempt to confirm and extend the earlier work of Carroll and Tullis1 who had reported the simultaneous occurrence of Ti and Zn in up to 17 per cent of the examined leucocytes in various hematologic diseases. It was concluded that the earlier results1 were seriously affected by the presence of contaminants which, for the most part, were probably derived from materials present on the Si discs used as substrate material, from room dust or from improper handling. A thorough study of the possible sources of contamination revealed that Zn and particularly Ti were present on or in many of the materials used in these experiments. Only if external sources of Ti and Zn were avoided by careful sample preparation and handling were unambiguous results forthcoming. Twenty-three abnormal blood samples studied herein failed to show Ti and/or Zn in any leucocyte: nine of these which were collected on clean substrates in dust-free areas were, in addition, virtually free of contaminants or other noncellular materials. The examination of two samples provided by K. Carroll1 revealed that the simultaneous presence of Ti and Zn occurred primarily in noncellular material. Considerable information concerning blood and blood chemistry will be derived from electron microprobe examination, but, as discussed herein, careful consideration of probe operating variables and sample preparation will be essential.
