3 replies to this topic

[lotus]

Hello,
Today I made 10X MOPS buffer for running RNA gels. I followed the standard recipe given to me by another person, and I checked it up online and found the exact same recipe recommended everywhere. I autoclaved the buffer, but it has turned yellow after autoclaving. It was colourless before. I have stored it at 4 C. Should I wrap it in Aluminum foil? Is the yellow colour a  problem?

[HomeBrew]

MOPS buffer turns yellow as it degrades (oxidizes).  It will turn yellow with age, and on long exposure to light, and, apparently, when autoclaved.

Are you sure that you were supposed to autoclave the solution, and not filter sterilize it?

Looking around on the web, it appears people have used "yellow" MOPS in RNA gels without difficulty (straw-colored yellow, anyhow -- I don't know how yellow your solution is...), but were it me, knowing that MOPS turning yellow is a sign it's oxidized (degraded), I wouldn't use it -- I'd make some fresh stuff up, filter sterilize it, and store it protected from light (as is recommended in Maniatis and in Current Protocols).

The buffer is easy to make, aquiring the RNA sample is hard...

[hsb31]

lotus, on Feb 26 2010, 06:15 AM, said:

Hello,
Today I made 10X MOPS buffer for running RNA gels. I followed the standard recipe given to me by another person, and I checked it up online and found the exact same recipe recommended everywhere. I autoclaved the buffer, but it has turned yellow after autoclaving. It was colourless before. I have stored it at 4 C. Should I wrap it in Aluminum foil? Is the yellow colour a  problem?

MOPS turns yellow after autoclaving, but still is used for RNA gels without problems.

[merlav]

MOPS can't be autoclave thats why it change color.  You autoclave the water(DEPC treated) and the recipient where it will be but not the buffer.  The Buffer should be filtrate!!!!So don't use it.  Prepare a new batch.  making MOPS sometime is a hassel if have the money buy it 10X and just dilute.