Using imprints from a plate carrying bacterial colonies, you can select streptomycin-resistant mutants and prove that such mutations do not originate as an adaptation. These imprints need to be used:

Explanation

Streptomycin is a broad-spectrum antibiotic (active against both Gram­positive and Gram­negative bacteria) and was the first effective drug against tuberculosis, but its use is limited due to the development of resistant strains and toxic side ­effects. The bactericidal action of streptomycin, as with other aminoglycoside antibiotics (e.g., neomycin), is through selective inhibition of protein synthesis on 70S ribosomes. To check the resistance of mutants against streptomycin they must be grown on plates with streptomycin. Only those bacterial colonies will propagate from the master that they are resistant to the antibiotic.