Immuno electron microscopic diagnosis of potato virus M

Solid and liquid phase immuno electron microscopy (SPIEM and LPIEM) for PVM detection were tried on clarified virus-extract (CVE) and clarified virus concentrate (CVC) preparations. CVC preparation through polyethylene glycol (PEG) precipitation was found satisfactory when clarification did not employ Ca₃ (PO₄)₂ or solvents. CVE preparations revealed plenty of virions both in SPIEM and LPIEM. Maximum trapping was found when pH of the extraction buffer and trapping antiserum, respectively, were 6 and 7 or 8 while best decoration was obtained with antiserum at pH 6. The best clumping of virions was observed with pH 7 of extraction buffer and pH 6 of the antiserum. The present investigations appear to be the first report for optimum IEM diagnosis of PVM.