I am planning to run an experiment that requires me to monitor growth kinetics in aerobic bacterial communities over approximately 7 days. The communities should have between 30-100 species consisting of both gram-positive and -negative bacteria. I have composed a carbon limited defined media to cultivate the community that simulates a natural environment and therefore the obtained bacterial density is low compared to what one obtains with for example tryptic soy broth (between 1-3 million bacteria/mL).

I have tested dyes from Biolog (dye A, B, E, F, G and H) but obtain almost no colour change. I suspect this is due to the low bacterial density.

Does anyone have suggestions for dyes that:

1) change colour proportionally with growth/respiration

2) have little effect on growth

3) can be measured real-time over a week

I am also open for suggestions for end-point measurement dyes.

Any suggestions are much appreciated!

Best regards,

Madeleine Gundersen