Loading well DNA 28S rRNA 18S rRNA 5s rRNA tRNA. other small RNA molecules FIGURE 4.2 Agarose Gel Electrophoresis of Human Total RN A total RNA sample isolated from whole blood is subjected to 1% formal mide-agarose gel electrophoresis. Bands representing 18S, 28S. 5S RN and contaminating dna are indicated with arrows