PEG sensor chip storage

Hi everyone,

Quick question on sensor chip PEG (from Cytiva). Their official FAQ says storage after opening or use "has not been investigated". Has anyone here actually stored an opened or used PEG chip and gotten it to work reliably later? Trying to figure out if the usual CM5 rules actually hold for the PEG surface, or if there's something PEG-specific to watch out for.

Thanks in advance!

After your final regeneration (or after the last run), flush the chip with running buffer (the same buffer you used during measurement). Do not let the chip dry. Keep it continuously wet.
Store at 2–8 °C in a closed container in the same flow buffer but without detergent.
Main point is that the immobilized ligand must survive the storage. That is one thing you should test when you reuse the chip.

Arnoud

Hello Aneta,

I've been working with gold nanostructured chips, which I functionalize with a PEG layer and then attach my ligand molecule (a small one, ~441 g/mol). We use microfluidics and the channels are created by two layers, so those areas are "protected". I keep them in the fridge after using them and the response even after 1 year is ok, the signal goes a little bit down but still works.

However, I bet it is a little different when using proteins or antibodies.

We also tested the COOH chips from Affinité Instruments after the expiration date. We hydrated them to see if they were still functional, and we successfully attached our ligand to the surface.