Amino modified oligonucleotide and PEG gel (- COOH) were conjugated using NHS / EDC, but the gel was not uniformly fluorescent but partial partial points could be taken. It seemed like I took a point with a green highlighter.

There are no rotator in the laboratory, using tape, fix the rack of the eppendorf tube to the vortexer, and react with the vortexer. Shacking is impossible because the amount is too low.

How can amine coupling be even on the gel surface?

+Oh, I didn't mentioned about condition...

concentration of oligonucleotide: 5uM(in 1X PBS)

concentration of FAM-DNA: 100nM(in 3X SSC)

vortexing when add NHS/EDC: 15min, NHS and EDC is 100mM, both.

coupling with oligonucleotide: 2h, durong vortexing

buffers use when activation: 0.1M MES(pH 4.7)

coupling is runing at 1X PBS, and hybridization is running at 3X SSC.