Yellow precipitation in Licor Blocking buffer

[histonerunner]

Has anybody used Licor Blocking Buffer? I have been reusing Licor Blocking buffer but noticed that there is some yellowish precipitation on the bottom. If I shake it, it seems to dissolve in the solution. What could this be? Will it affect the blocking?

[shawnmischnick]

Hello,
LI-COR does not recommend re-using the Blocking Buffer. Always use fresh. There is lot to lot variability with fresh blocking buffer, which may include the yellow precipitation you are seeing. The precipitation is usually lipids that have come out of suspension. Placing it on a gentle shaker for an hour will cause the lipids to go back into suspension. This should not affect the performance of the blocking buffer. Hope this helps!

[Ana_Lonic]

We are also using Licor block buffer and sometimes notice the precipitation but it doesn't seem to have an effect on blocking performance. I tend to use fresh buffer for the initial block and then re-use that block buffer diluted 1:1 with PBS for subsequent antibody incubations.