Determination of the relative abundance of mRNAs in a polyribosome-associated pool

Polyribosomal fractions derived from P25 mice were the starting material for IPs of the FMRP protein and associated mRNA. Therefore we wanted to determine the relative abundance of all mRNAs in the starting pool for the IP as a denominator with which to compare the IPed material. [mRNA profiling]: We prepared polyribosomes on sucrose gradients in duplicate from 2 FVB WT mice, age P25, and purified RNA from polyribosomal fractions of each of the two gradients.