Figure 5.
Detection of PSA mRNA by reverse transcription-coupled LAMP (RT-LAMP). Various numbers of LNCaP cells were mixed with 106 PSA-non-producing K562 cells and total RNA was extracted. RT-LAMP was carried out in the same reaction mixture as for M13mp18 DNA amplification except that 1.6 µM each PSAFIP and PSABIP, 0.2 µM each PSAF3 and PSAB3, 0.8 M betaine, 5 mM DTT, 16 U Bst polymerase, 100 U ReverTra Ace (Toyobo) and 5 µg of extracted RNA were used. All the above components were mixed at once on ice and were incubated at 65°C for 45 min. The products were electrophoresed in 2% agarose gel followed by SYBR Green I staining. + and –, RT-LAMP carried out in the presence and absence of Bst DNA polymerase or ReverTra Ace, respectively. Lanes 8 and 9, the same products (1/5 vol) as in lanes 6 and 7, respectively, but digested with Sau3AI; lane M, 100 bp ladder (New England Biolabs).