My RNA lenth is 30 mer. I want to custom generate an RNA laddr with Ribonuclease A digestion of the 30mer to creat 4, 6 18 and 26 mers. How can I do that.?
Interesting idea, however i know that Rnase A / T1 and other RNases do not cut specifically like Restriction Enzymes. So the only thing you could try, but I doubt it would work is do a Time Course of digestion.
ie try cutting it for a few seconds to a minute. I still doubt you can know how long it will need and what fragment size you will get so....
the cheapest and easiest way to get an RNA ladder is to buy one. they are quite cheap and your supervisor should pay for it. I would go that way.
Fermentas has 100-1000 nucleotide RNA ladders [Only registered users see links. ]
Although the best one I found is this RNA ladder with Fragment sizes (base): 30,26,22,18,14 nucleotides.