A Lab Technician Has Four Strains of Bacteria A) Minimal Media with Leucine and Streptomycin
B) Minimal Media

Multiple Choice

A lab technician has four strains of bacteria. Although he forgot to label them, he knows that they include one F+ strain, one Hfr strain, one F' strain, and one F- strain. He observed the following results after plating these strains on different media. Which of the following plates can be used to identify the F- strain? $$\begin{array} { | l l l l l l | } \hline \text { strain } & \text { his } & g \text { gu } & \text { cys } & \text { leu } & \text { str } \\\mathrm { F } ^ { + } & + & + & + & - & + \\\mathrm { Hfr } & + & + & + & + & - \\\mathrm { F } ^ { \prime } & + & + & + & + & - \\\mathrm { F } & - & - & - & + & + \\\hline\end{array}$$

A) minimal media with leucine and streptomycin
B) minimal media with histidine, glutamate, and cysteine
C) minimal media with histidine, glutamate, cysteine, and streptomycin
D) complete media
E) minimal media with streptomycin