THE DEVELOPMENT AND EVALUATION OF FREEZE-FRACTURE CYTOPLASMIC MACERATION FOR THE SEM TO INVESTIGATE ALGAL ULTRASTRUCTURE/

Freeze-fracture/cytoplasmic maceration (FF/CM) to expose chloroplast u ltrastructure for the SEM was developed for the green alga Enteromorph a intestinalis (Linnaeus) Link, and the results were compared with con ventional TEM preparation. Preliminary investigations showed that the method used for higher plants was inadequate to expose algal chloropla st membrane detail, but, by decreasing the molarity of the buffer duri ng maceration to make it more hypotonic relative to the tissue, suffic ient cytoplasmic extraction was accomplished in 7 days using osmium te troxide at a lower concentration than suggested in previous work. Post -maceration in tannic acid was omitted from the processing after the p reliminary study to assess its effects on the final images, and conseq uently preparation time was shortened dramatically and now compares fa vourably with the time taken to prepare material for the TEM. Ultrastr uctural integrity is preserved and is consistent with normal TEM prepa rations. (C) 1997 Elsevier Science Ltd. All rights reserved.