This is the second in a series of posts analyzing Rosetta Genomics stock. If you haven’t already, you may want to read my primer on what a micro RNA is and how companies can capitalize on them.

There’s really two ways to find a miRNA. The first is to isolate RNA from the cells of tissue (or a cell line grown in the laboratory). Then purify the relatively small miRNAs from the rest of the RNA molecules. Reverse transcribe the miRNAs to make DNA molecules and ligate the newly synthesized DNA molecules into a vector and transform that into bacteria. Grow up enough bacteria to isolate the vectors with the miRNA sequence inserts and sequence them. After all these steps, you’ll have the most abundant miRNAs in the one tissue that you isolated them from. You’ll miss the miRNAs that aren’t highly expressed and you’ll need to repeat the process for every different cell type that you want to find miRNAs in. As you can see, it’s a relatively inefficient and fairly costly way to find a lot of miRNAs.

Rosetta Genomics has decided to take a different line of attack. They used a computer approach to define potential miRNAs based solely on sequences in the human genome database and then tried to figure out whether they were real (were expressed). The approximately 10,000 potential miRNAs they identified due to their sequence were put on microarrays and their expression was tested in multiple tissues and body fluids. They have identified 1,500 potential miRNA sequences that showed expression in one or more tissues. Since the microarray can have a high background which may lead to false positives, they further confirmed them through either quantitative RT-PCR or by cloning and sequencing them. To date, they’ve confirmed 320 through this method, which is half of all the miRNAs that have been discovered. And, since they have certainly not tested every tissue possible, there’s potential for them to identify even more tissue specific miRNAs by checking additional tissues with their array.

With patents on each of the miRNAs they’ve discovered, Rosetta Genomics certainly has a lot of intellectual property. I’ll look at exactly what they’re planning on doing with that IP in the next couple of posts.

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Aside: I have a post up in the Festival of Stocks at Investor Trip. If you’re looking for ideas of non-biotech stocks to investigate further, go check out the festival.

Filed under: Rosetta Genomics (ROSG)