Question: I want to post my manuscript to bioRxiv before submitting onto formal journals, but I still have several concerns:

1. Can I claim I am the first for the discovery by posting my findings on bioRxiv ?
2. Similarly, is it a feasible way to prevent others from publishing ealier than me on the same topic ?
3. Are there any risks of having my research scooped after posting my manuscript on bioRxiv ?

Thanks and Best regards,

Michael

Answer: 
In fields that use [arXiv](https://arxiv.org/), publication in arXiv does establish a definitive date-stamp on the work (and an accompanying archival DOI) that is generally understood and respected by practitioners in the field. Nobody could reasonable "scoop" a work published there without being called on it by their peers.

bioRxiv is intended to provide the same for biology-related fields and technically does so. The culture of those fields, however, is often not yet as accepting of the idea of pre-publication and incrementally evolving works. Hence, for example, the much greater concern with the ideas of "priority" and "scoop" to begin with. A few journals still even consider sharing a pre-print in bioRxiv to be a sort of "self-scoop" that prevents you from submitting for peer review in that journal!

Still, the only way to change this culture is to embrace more open and sharing practices. I would advise checking whether others in your sub-field use bioRxiv, checking the publication policy of your target journal in [SHERPA/RoMEO](http://www.sherpa.ac.uk/romeo/journalbrowse.php?la=en&fIDnum=%7C&mode=simple), and checking if your co-authors are amenable to pre-print sharing. If you see others in your subfield sharing, and if there is no veto from the journal or co-authors, then go ahead!
Putting immature article before peer review is not proof of discovery.
If yes, we can easily scoop other's findings by posting quick, short and sloppy article in Preprint server (after knowing their data for example in some research conference) .

Also, the benefit of Preprint server is that researcher can publish there data quickly before long peer review and publication process.
However, in reality, most of the author post their articles in preprint sever when they noticed that some other group were also working on the same topics and wanted to insist their priority. This is quite ugly and selfish motivation.

All paper needs to go through peer review when the paper needs to be polished. 
Even though that is time-consuming, this process is equally required for all academic paper. 
Therefore, posting article in preprint server after knowing some competition is dirty scooping.