Figure 2.

Direct comparisons of RNA yield, purity, and integrity using different RNA extraction procedures. Pairs of clinical samples were pooled, divided into two equal aliquots, and extracted in parallel with RNeasy or Trizol. RNA concentration and yield were calculated from absorbance at 260 nm. In A, values in italics were obtained after an additional acidic phenol-chloroform extraction of the Trizol-extracted RNA. RNA size was assessed by Agilent gel electrophoresis of samples extracted with RNeasy (B), and Trizol (C). One ul was added to each lane, corresponding to approximately 25 ng (B) and 100 ng (C). Numbers 1 to 3 above each lane in B and C correspond to the samples number in A; matched numbers represent identical aliquots extracted in parallel. Ribosomal RNA was used as the molecular weight maker (lane 0); positions of 28S and 18S rRNA are indicated on the left. Arrow (right) indicates 200 bp.