[Myrddin]

The media supplier recommends a CO2 atmosphere with 35-37C temperatures. Tube caps open for the first 5 days, then seal tight to prevent media dehydration. Protect from light during incubation. In vivo, they prefer to be intracellular. That makes them hard to treat.

A research at this link has had success stimulating the M. leprae organism with thyroxine containing Dubos medium prior to culture on a Lowenstein-Jensen slant. Incubation time is 8 to 16 WEEKS.

[exDemMom]

Incubation time is 8 to 16 WEEKS.

And I thought it was tedious growing Leptospira, which had to be cultured for days!

Yeast in selective media could take days to weeks to grow, too.

I've never tried culturing anything that took several weeks to grow. It would be very disheartening if a culture failed.