Chemi-Northern using biotinylated DNA probes detects endogenous messenger and noncoding RNAs. (A) Total RNA was purified from HCT116 cells and titrated (50, 100, 1000, 2500, and 5000 ng) onto a formaldehyde agarose gel, followed by Chemi-Northern blotting using 5′ biotinylated DNA oligonucleotide antisense probes for endogenous β-actin (ACTB) mRNA at 85 sec exposure (1812 nt + pA tail, upper panel) and 7SL ncRNA at 1 sec exposure (299 nt, middle panel). EtBr staining of rRNAs is shown in the lower panel. Quantitation and graphs showing the linear fit of the total RNA mass (ng) versus signal intensity of the β-actin mRNA (B) and 7SL RNA (C). (D) Total RNA of Drosophila DL1 cells titrated and endogenous 7SL (299 nt) and detected via Chemi-Northern blot at 1 sec exposure. (E) Quantitation of signal intensity of 7SL RNA relative to total cellular RNA.
