Differential recovery of mRNA transcripts using acid organic extraction techniques: quantification of abl mRNA abundance in the blowfly, Calliphora erythrocephala.

A commonly used RNA isolation technique that employs a single-step acid phenol-chloroform extraction (Chomczynski and Sacchi, 1987) produces a different distribution pattern of C. erythrocephala c-abl (Ceabl) transcripts following Northern blot analysis than methods that rely on phenol-chloroform extraction at basic pH (Jowett, 1986). Only Ceabl transcripts of 10.5 kb and 6.5 kb are recovered, while Ceabl transcripts of 9 kb and 4.4 kb are lost, when acidic phenol-chloroform methods are used. All tested extraction methods which do not rely on phenol-chloroform extraction under acidic conditions can recover Ceabl transcripts of 10.5 kb, 9 kb, 6.5 kb and 4.4 kb. The reason for this discrepancy is apparently due to differential loss of mRNA at the phenol phase and/or interphase boundary during the acidic extractions.