BAC-8 - resazurin MIC (A madurae, N brasiliensis, S somaliensis, S aureus)

[KlementineJBS]

Master page is #260

Things to try

• try 5, 10, 20 and 30 uL of resazurin dye
• try 75 uL + 75 uL of antibiotic + inoculum so that it fits into the wells better
• ensure that there is actually decent growth!!
• do resazurin line for S. aureus so that I can see the pink colour

In this case, I will only adjust the amount of dye so that it is more comparable to #256. Future attempts can include the altered volumes.

Plate plan

[KlementineJBS]

25.11.24

Made up plates as described but didn't add resazurin - wasn't sure about stability etc. Probably fine but will add it tomorrow anyway. Used a combination of MH broth opened last Friday and a new bottle opened today.

[KlementineJBS]

26.11.24

Made up all inoculums as usual. Same inoculums used as in #263, and A madurae made up from a plate subbed 21/11 as well.

Accidentally inoculated Am negative control in column 1.

Placed in 37 C incubator at 12 pm.

Photo taken before incubation:

[KlementineJBS]

27.11.24

Can already see clear colour change in S aureus. Will read on Friday (72 hrs) along with N brasiliensis and S somaliensis.

[KlementineJBS]

28.11.24

From above

From below

[KlementineJBS]

29.11.24

2024-11-29 BAC-8 (Sa) rerun.xlsx 2024-11-29 BAC-8 (Sa).xlsx 2024-11-29 BAC-8 (Nb, Ss).xlsx BAC-8 resazurin MIC.zip 2024-11-29 BAC-8 (Nb, Ss) rerun.xlsx

After centrifuging and transfer:

[KlementineJBS]

02.12.24

Plates after 6 days growth (left) side-by-side with plates with 3 days growth (right, from #264). Left-hand plates have had 100 uL removed, except for A madurae columns.

A madurae plate closeup.

Both plates from beneath (N brasiliensis has paper towel):

Cross contamination is still an issue.