I am trying to isolate mRNA from periodontal ligament and alveolar bone, it is kind of tricky as the PDL is a fibrous ligamentous highly cellular tissues. However, it is 0.5-1mm thick and the maximum weight you can get is 0.01-0.02g, which renders the starting material very limited. As for bone, I'm afraid that the procedure might be complicated by the mRNA sticking to the mineral crystals. Any advice form experience would be really appreciated.