Distinguishing stringent from relaxed?

[M.J. Pallen]

I  am in the process of transduing a Tn10 relA mutation from one strain of 
Salmonella into another. Does anyone have a handy way of scoring the 
relA-negative phenotype, so that I can check that I really do have a relA 
mutation in the second strain? Cahel & Rudd in Neidhardt's E. coli & S. 
typhimurium book mention SMG medium. Is this the best way of 
distinguishing stringent from relaxed strains?

Mark 
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Dr Mark Pallen, Senior Lecturer in Medical Microbiology, 
St Bartholomew's Hospital Medical College, London, EC1A 7BE
currently at the Dept of Biochemistry, Imperial College, London, SW7 2AY 
email:m.pallen at ic.ac.uk  
phone: day ++44(0)1715945254, eves ++44(0)1815057937, FAX ++44(0)1715945255
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                            lag                   ellum
                             f   e               lag 
       ecoliecoliecoliecoliecoli  l            mf 
      cecoliecoliecoliecoliecolii  l          u 
      eecoliecoliecoliecoliecolic   umf     ll      
      coecoliecoliecoliecoliecoli      l  ge 
       ecoliecoliecoliecoliecoli        a         
         p                   f       fl g 
        i                   l     lum   el
       l                     agel         lu
      u                                      mflagellum
     s
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