I want to extract proteins as per normal using RIPA lysis buffer from mouse brain. Can I use the remaining pellet for extraction of insoluble fraction of beta-amyloid using sequential extraction methods with 2% SDS or 70% formic acid?
I am confident that you can still extract beta-amyloid from your RIPA-lysis pellets. However, you should be aware that you will get a different fraction composition than in a regular sequential extraction where you use PBS or DEA buffer in the first step. Other than PBS or DEA buffer, RIPA buffer will partially solubilize membrane bound amyloid due to its detergents. So basically what you will get is not the insoluble or membrane bound fraction of amyloid, but the fraction that hadn't been solubiluzed by the RIPA buffer. If you know what I mean...