Over the last couple of years, the number of companies or institutes creating their own magnetic bead based purification kit has increased. Main incentive to produce in house kits is the cost saving on the reagents, where commercially available kits typically are more expensive.
However, there are some advantages when considering commercial kits, especially since homebrew kits are cheaper when considering reagent costs, but in some cases as expensive or even more expensive when calculating the labor hours into the costs.
The second advantage of a commercial kit Is the reproducibility and quality of the product. Companies providing these kits need the quality to be good and reproducible between batches. As a result, these kits are produced in a monitored and quality controlled environment.
Is it possible to make home made beads for RNA? This is possible as long as you work in a RNase free environment and with chemicals that are produced and kept RNase free. So it is possible but it is also possible to order commercial beads that are produced RNase free.