VIEW ARTICLE

Effects of Preparative Procedures on the Preservation of Tobacco Mosaic Virus Inclusions. Willem G. Langenberg, Plant Pathologist, Agricultural Research Service, U.S. Department of Agriculture, University of Nebraska, Lincoln 68503; Helen F. Schroeder, Laboratory Technician, Department of Plant Pathology, University of Nebraska, Lincoln 68503. Phytopathology 63:1003-1010. Accepted for publication 15 February 1973. DOI: 10.1094/Phyto-63-1003.

Tobacco mosaic virus (TMV) inclusions could be preserved consistently in the crystalline state if five variables were met in the following order: (i) continuous light-treatment of turgid plants for 36 to 144 hr; (ii) Hepes (N-2-hydroxyethylpiperazine-N’-2-ethane sulfonic acid) citrate as the fixative buffer; (iii) chromic acid-formaldehyde as the fixative; (iv) acetone as the dehydrant, and (v) Epon 812 or Spurr low-viscosity resin for final embedding. No stabilizing influence of divalent cations or anions on the crystalline inclusions was found. Inclusions were dispersed, either partly or completely, by dehydrating agents other than acetone and by embedding resins other than Epon 812 or Spurr low-viscosity resin. Phosphate-buffered 3-5% glutaraldehyde, or Karnovsky’s fixative, invariably dispersed TMV inclusions, irrespective of pretreatment or postfixation of the tissue. The entire preparative process could be followed in selected haircells.