Tryptic soy agar (TSA) + VRG
The image shows a combined TSA and VRG agar plate. On plate A, no bacteria have been streaked out, while Escherichia coli has been streaked out on plate B. - Click on the image to enlarge it.
Applications:
"Tryptic soy agar (TSA)" is a general medium, which is used for isolation and enumeration of many different bacteria, among others, E. coli.
The medium contains:
- casein peptone (contains amino acids and peptides)
- soya peptone (contains amino acids and peptides)
- NaCl (contributes to the osmotic balance)
- agar (gelifying agent)
- water
The final pH of the medium should be 7.3.
Other comments:
TSA is often used in combination with VRG agar. TSA is then mixed with the sample to be analyzed at around 40°C and poured into the plates. After preincubation for 1-2 h at ambient temperature, the TSA is overlayed with VRB agar and the incubation is then continued at 37°C.