when to transplant

Any harm in transplanting into 6 packs immediately after germination (ie, before the first leaves appear)? I've heard that it's bad if you wait too long to transplant, but I'm curious if it harms the plants to do it earlier... (annuals and veggies)
Thanks,
Mara

You can transplant at any time. I would try to get a little bit of soil around the roots when they are this young. Normally, transplanting is done after first set of true leaves, or even until the first few sets of leaves when the seedlings become crowded in the seed flat.

Thanks for this info and my other post about the size of containers. I'm excited - I've had good germination, and I don't want to kill all my plants by transplanting them at the wrong time or in the wrong way. It's my first time growing a few things from seed.
-Mara

They are extremely delicate before their first true leaves, I'd personally err on the side of caution, here we traditionally transplant when the plant has 4-8 sets of new leaves.

I usually transplant larger seedlings (Cabbage size) as soon as the first true leaves appear. On very tiny seedlings, I wait a little longer. Tiny seedlings such as lobelia are impossible to handle prior to getting a couple of leaves.
George