In general we have the experience that RANKL is expressed quite low in bone samples as well as in blood/serum. OPG should be higher and easier to detect. We always use Trizol isolation for liquid samples, with column isolation kits we were not succesfull. If you have further questions dont hesitate to ask.
Kai Oliver Böker ,thank you so much. Have you ever had any experience in extracting osteogenic biomarkers such as Runx-2,Ostoecalcin or BMP-2 from serum?And could you please share the brand and type of the reagents you used when extracting OPG,Runx-2, OC and BMP-2? Hehighly appreciated your help!
So far we only checked RANKL and OPG in serum and bone samples. For RNA isolation we used Trizol, for protein detection we used western blot (semi dry) detection. Do you have a specific question for any step? Which protocols did you use so far?