On the lability of poly(A) sequences during extraction of messenger RNA from polyribosomes.

Extraction of mRNA from polyribosomes with sodium dodecyl sulfate and phenol at near neutral pH results in a considerable loss of the poly(A)-containing mRNA from the aqueous phase, and also in cleavage of poly(A) from the mRNA. The loss and cleavage are associated with some specific proteins in the polyribosomes, and can be avoided if these proteins are destroyed before extraction or if extractions are done with chloroform plus phenol rather than with phenol alone.