Are you interesting in knowing if you descend from the immigrant John Whitney of Watertown, MA, Henry Whitney of Long Island, or of another branch?
The Whitney DNA Study Project, in progress since 2002, currently has a total of over 50 participants. By analyzing the results we have gathered so far, we now know that John and Henry were not related to each other, and that there were other Whitney families who were also probably not related. Each of these groupings has a "signature" DNA profile that we have been able to identify. By having yourself (or a male family member) tested, we can determine which of the groupings you belong to, which may help to focus your research.
The cost for a basic 12-marker test is $99.00 and requires a direct male Whitney descendant to be tested. Note that I am not affiliated with the company that does the testing, just helping to coordinate the project.
See the Whitney Research Group website at http://wiki.whitneygen.org/http://wiki.whitneygen.org/ and select the link to the DNA Project for further details.
Tim Doyle Whitney Research Group Website Co-host Whitney DNA Study Project Co-Administrator