STRAIGHTERLINE MICROBIOLOGY LAB
BIO250L LAB 7 FINAL PAPER 2026
QUESTIONS AND VERIFIED ANSWERS 100%
ACCURATE
⩥ Why must TSI test observations be made between 18-24 hours after
inoculation? Answer: It needs to incubate for that long in order to detect
the presence of sugar fermentation, gas production and H2S production
⩥ Difference between an acid and alkaline slant Answer: Acid slant is
yellow and alkaline slant is red
⩥ How is SIM medium used to detect motility? Answer: Motility is
present when the growth of the culture is not restricted in the stab line of
inoculation
⩥ What substrates are acted on in SIM medium in order for H2S to be
produced? Answer: Peptones and Sodium Thiosulfate
⩥ In addition to H2S production and motility, what other test can SIM
medium be used? Answer: Indole production
BIO250L LAB 7 FINAL PAPER 2026
QUESTIONS AND VERIFIED ANSWERS 100%
ACCURATE
⩥ Why must TSI test observations be made between 18-24 hours after
inoculation? Answer: It needs to incubate for that long in order to detect
the presence of sugar fermentation, gas production and H2S production
⩥ Difference between an acid and alkaline slant Answer: Acid slant is
yellow and alkaline slant is red
⩥ How is SIM medium used to detect motility? Answer: Motility is
present when the growth of the culture is not restricted in the stab line of
inoculation
⩥ What substrates are acted on in SIM medium in order for H2S to be
produced? Answer: Peptones and Sodium Thiosulfate
⩥ In addition to H2S production and motility, what other test can SIM
medium be used? Answer: Indole production
