Agrobacterium tumefaciens GV3101 always give black pellets?

Jennifer Crismonika @Jennifer_Crismonika

05 January 2022 1 6K Report

I'm trying to make Agrobacterium competent cells, but I always get black pellets when I harvest them, on OD around 0.5, I have tried to change the centrifuge speed into just 3000/4000rpm, 3-10 minutes, also tried to slow the rotation into just 180 rpm. Does anybody has another suggestion? Thank you very much!

Xi Jiang

Hi Jennifer,

it is normal to have a tiny bit of a black pellet at the bottom of the tube. If you continue with the procedure, the competent cells will work anyway.

Just to be sure, can you provide a picture of the pellet please?

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