Get the smallest scale available from your supplier. Even the smallest scale should be enough for more than 10000 reactions. I would not go for purification which may need a higher scale of synthesis as production is so good these days that desalted is almost always good enough for sequencing

would 20 nmol be good? I had some recommendations about 25nmols... any thoughts? (it's for 16s sngs sequecing)..

thank you!!!!!!

20nM is plenty. I think the recommended for a single read sequence is 4.2pM so 20nM should give you about 5000 sequencing reactions and they are very cheap if you eventually do need more than this in a few years time

thank you Paul!!it really helped me!