How can i preserve squid ink
From what I understand you should be able to extract the ink and freeze it for later use. Users on this forum suggest extracting the ink and then freezing. Another person here says:


  I save my ink from freshly cleaned squid and just freeze it


So it looks like your best bet would be to extract the ink from the sacs into a suitable freezer container and freeze it.

Freezing will definitely help it to last longer as the shelf life of squid in the refrigerator is 1-2 days. You can extend this to 3-5 months in the freezer. I'd imagine the squid ink would have a similar shelf life.