Hello,

I conjugated Avidin and 5'-biotinylated aptamer (ssDNA) in a PBS solution. However, after the purification steps, I was unable to detect the signal for ssDNA in the UV-Abs spectrum. Before the interaction, I could see the Avidin and ssDNA peaks in the UV spectrum. However, after incubating them together and purifying them (via centrifugation), I no longer observed the peak for ssDNA.

Are there any simple methods or instruments that can be used to quantify and identify Avidin and ssDNA?