Well, I may be biased but I would not go back to tubes for routine use for anything. In my view, the biggest problem with tubes is the transcription of the results. there is no way that you can ever check up afterwards if what you wrote down as 4+ positive really was - or was it a 2+? Was the control positive, but missed? etc etc. the thing with gel is that even if you're working manually you can still photocopy the results if you don't have a little reader. the reader is better because it will read and interpret the results for you and you have traceability if anything is manually changed as well as a record of who read the results etc. the results can then be transmitted directly to your laboratory information system. But even if you don't have this, there is nothing to stop you from photocopying the cards and storing in your log book. That way, if there is any question at a later date, you can still see the images . Of course this doesn't stop you from mixing up the tubes and pipetting in the wrong card - but then the same goes for tubes.

Good points Anna.