PH and heat stability of foot and mouth disease virus used in vaccine production in egypt

Rates of inactivation of tissue culture derived FMDV.type 01/2/72 Egypt at various pH levels and temperatureswere studied.1- The ranges of pH ahd temperature investigated were between pH 5,0 and pH 9.b. and between 26°C and 65°C.2- The effect of l-moi Mgc12 and 2-mol Nacl at temperatures of 37°C and 50°0 on FMDV typa °1/2/72 Egypt was recorded.3- The infectious (only 110g ID50/ml) by heating virus tissue suspension at 26° C for 48 hours4- By heating the FIYillV at 37°C for 24 hours, the infcetiv” of the virus decreased by 2.510g ID50, while it decreased significantly if the tissue suspension of FMDV was heated at 37°C in the presence of salts. The rate of loss ofinfectious particles at the same virus for a short period of time (4 hours) showed a non remarkable loss of infectivity (0,75 to 1,25 log ID50/ml).5- ’rhe rates of thermal inactivation at 50°C for differentperiods (starting from 30 to 120 minutes) and in different buffers were studied. The loss of infectious property of FMDV °1/2/72 Egypt waS clearly demonstrated regardless the