Hi what kind of sequencing?

Good quality sequencing with the Thermosequenase and fluorescent dideoxy nucleotides requires about 100 ng per 1000 bp of purified PCR fragment. From what I see in your gel, the marker seems the 100 bp, so your fragments should be around 7-800 bp, which means you could sequence them with only 100 ng of PCR product. Now, it depends what you loaded on the gel: if it is 1/10th of your PCR reaction, probably after gel extraction you'll have enough to sequence (even though you've got quite a lot of Ethidium bromide there, so there is not much DNA on gel...), but if on gel you have the entire PCR reaction I would doubt it, mostly for well 5 and 6. In this case you should pool a few reactions or re-amplify your first reaction (which might have a higher chance to introduce mutations and increase the unspecific bands).