I should have read your question properly!
They need more light, more air circulation and no humidity domes.
I would be replanting these seedlings into larger pots and burying them up to half an inch below the cotyledons/round leaves, this will provide a lot more support and in time, the buried portion of stem will sprout roots and contribute to over all plant health.
If you are only using a desk light, this is your biggest problem, they need quality growing lights to thrive.
Cheers, Organoman.