Total RNA can be isolated from tissue samples using the Trizol protocol. RNA should be quantified for determining yield and amount to load per lane.
Make a 1.2% agarose/formaldehyde gel using MAE buffer.
To each sample of RNA, and the RNA ladder, add 10 ul of formaldehyde gel sample buffer (FGSB) and 1 ul of ethidium bromide at 400 ng/ml. These two can be mixed beforehand. Mix and spin. .
Heat samples at 65 degrees Celcius for 10 minutes, chill on ice, spin down briefly.
Place gel into electrophoresis chamber and fill chamber with 1x MAE.
Load wells with samples, and let gel run for 3 or so hours at 80-100 mA. The blue dye should run about 2/3 of the lane distance.
The RNA samples and ladder can be visualized under UV and photographed for records with a ruler being sure to note where the ladder bands are from the starting point. Also note if the sample bands are of appoximate brightness indicating similar quantities of RNA loaded and that the 28s and 18s ribosomal RNA bands are present.
Soak gel in 6 changes of depc dH2O for about 20 minutes.
Place gel into 10 SSC for 10 minutes.
Cut the nylon membrane to the size of the gel as well as two pieces of Whatman filter paper.