edc m 6 h compound of up to 426 37 daltons the reacting mixture is incubated at room temperature during 2 3 hours under constant stirring the synthetic product obtained the morphine 6 hemisuccinyl tetanus toxoid vaccine is then purified using standard dialysis procedures using 10 kda cut off dialysis membranes sigma aldrich against six changes of 6 liters of 0 1 m phosphate buffer solution ph 7 2 at 4 u00b0 c over a 48 hour period in order eliminate the by products formed during the reaction such as urea and the non haptenized edc m 6 h intermediate derivative once the purification of the morphine 6 hemisuccinyl tetanus toxoid vaccine has been completed the dialyzated solution is subsequently sterilized by filtration in 0 45 u03bcm pore size membrane filters gelman sci under positive pressure finally 1 ml aliquots of the filtered solution are dry frozen lyophilized in sterile glass vials sealed under vacuum and preserved under storage at 4 u00b0 c several agents used normally to stabilize and prevent degradation of conjugates during dry freezing and storage procedures e harlow and d lane antibodies a laboratory manual cold spring harbor laboratory new york 1988 can be added to the therapeutic formulation of the present invention of the bivalent vaccine against morphine heroin addiction examples of selected agents consist of jelly peptone dextrine methyl cellulose sucrose lactose maltose glucose fructose sorbitol glycerol manitol inositol citric acid tartaric acid polyethylenglycol and polyvinylpirrolidone among many others.