Another method would be to allow potassium to burn in the presence of chlorine gas, also a very exothermic reaction:

  
    
      
        
          2
          
          K
          +
          
            Cl
            
              2
            
            
              
            
          
          ⟶
          2
          
          KCl
        
      
    
    {\displaystyle {\ce {2 K + Cl2 -> 2 KCl}}}

References
Further reading
Lide, D. R., ed.
Genes conferring neomycin-resistance are commonly included in DNA plasmids used to establish stable mammalian cell lines expressing cloned proteins in culture. Many commercially available protein expression plasmids contain a neo-resistance gene as a selectable marker. Biosynthetic pathway
Neomycin was first isolated from the Streptomyces fradiae and Streptomyces albogriseus in 1949 (NBRC 12773). Neomycin is a mixture of neomycin B (framycetin); and its epimer neomycin C, the latter component accounting for some 5–15% of the mixture. It is a basic compound that is most active with an alkaline reaction. It is also thermostable and soluble in water (while insoluble in organic solvents). Neomycin has good activity against gram-positive and gram-negative bacteria, but is ototoxic. Its use is thus restricted to the oral treatment of intestinal infections.Neomycin B is composed of four linked moieties: D-neosamine, 2-deoxystreptamine (2-DOS), D-ribose, and L-neosamine. Neomycin A, also called neamine, contains D-neosamine and 2-deoxystreptamine. Six genes are responsible for neamine biosynthesis: DOIS gene (btrC, neo7); L-glutamine:DOI aminotransferase gene (btrS, neo6); a putative glycosyltransferase gene (btrM, neo8); a putative aminotransferase (similar to glutamate-1-semialdehyde 2,1-aminomutase) gene (btrB, neo18); a putative alcohol dehydrogenase gene (btrE, neo5); and another putative dehydrogenase (similar to chorine dehydrogenase and related flavoproteins) gene (btrQ, neo11).