SOC vs TB in transformations - (Feb/26/2013 )

Hi all, wondering if its absolutely required to use SOC for transforming BL21, XL1 Blue and XL10 Gold cells. I tried it with TB and although I used TB for DH5alpha transformations before with no issues it didnt work here. Any ideas?

SOC is an enriched medium containing glucose, while TB doesn't contain it. Some competent cells may be more sensitive to the initial growing conditions. And as I remember, XL10-Gold cells even require NZY+ broth for transformation (also containing glucose), however when I was doing mutagenesis I didn't have it and used SOC instead and got some colonies. But probably using the right medium would improve the transformation efficiency.