X-ray microanalysis of growth cartilage after rapid freezing, low temperature freeze drying and embedding in resin

This paper reviews the work undertaken on the X-ray microanalysis of growth cartilage particularly in relation to matrix calcification. Attention is focused on the methodology available to accurately localize and retain the elements of interest. A method is described which involves rapid freezing, low temperature freeze drying in a custom built device, and embedding in Spurr resin. The results show that little tissue damage occurs and that elements of physiological interest are accurately localized at the sub-cellular level. Where damage occurs to chondrocytes as a result of freezing, however, dense intra mitochondrial granules are seen suggesting a phase transformation takes place resulting in the precipitation of calcium phosphate. Further improvements may be made in retaining the more labile elements such as K by using resins which polymerize at low temperature.