Evaluation ofT3Coliphage Injuries andEfficacy of Selected Materials inPreventing Them

A procedure was developed toanalyze theinactivation ofcoliphage T3during freeze-drying andsubsequent rehydration. Theamountofgrossdisruption ofthe phage ascompared withtheamountofphageremaining intact was evaluated by cesium chloride density gradient centrifugation. Theamountofphagematerial abletoadsorb tohostcells andtheresidual infectivity after thedrying were also evaluated. Theseanalyses madeitpossible todetermine theamountofphage material (i) degraded toprotein andnucleic acid, (ii) intact orlargely intact, (iii) capable ofadsorption on hostcells, and(iv) infective. Thecapacities ofcasein hydrolysate, ascorbic acid, thiourea, bovine albumin, polyethyleneglycol, raffinose, inositol, and lipoproteins toprotect T3bacteriophage fromthestress offreeze-drying were investigated. Lossofinfectivity bymammalian viruses (3, 59,11,14)andbacteriophages (2,10,12,16)asa result offreeze-drying hasbeenreported. The nature ofthenoninfectious material resulting fromfreeze-drying bacteriophage hasbeeninvestigated toalimited extent byelectron microscopy., (4,15), butnotbyquantitative physical procedures. Thepurpose ofthisstudy wastoinvestigate, byuseofbothphysical andfunctional criteria, theeffect offreeze-drying onbacteriophage T3andtodetermine howadditives modify these effects. Suchinformation wouldbeuseful in developing procedures forprotecting bacteriophageandpossibly other viruses fromdamage