I do qPCR often using the SYBR green. Everytime, I have to prepare the mix which contains the Primers, Water and the SYBR green mix. I wonder if this mix is stable in -20? Can I prepare a stock of for example 1 or 2 mL and put it in -20 degrees for several uses? or does it have to be prepared fresh everytime?

Second question is, if I wish to run the sample on agarose gel, can I also have the gel prepared in bottles and stored in -4 degrees and then melt it down only before casting?