Atto 565 (Figure 1) can be used as an alternative to Alexa Fluor 568 or Alexa Fluor 546.
Figure 1. Structure of 5'-Atto 565 (R = sequence).
metabion offers Atto 565 in its DNA and RNA portfolio (as a 5'-, 3'- or internal Atto 565-dU or -dC modification):