Just to clarify, I am not aware of the exact details on the Clan's SNP testing but I was thinking of the fact that the connection between L1065 and the Scots clade is now more or less confirmed and can be at least referred to as the apparent truth, so to speak. The Scots clade itself was I think never a controversially defined clade: even if there might be grey areas, there is certainly a core group which is quite homogeneous, and certainly includes the relevant MacGregor, Campbell, Buchanan, etc etc lineages.
Originally Posted by Jean M
One I know first hand: the chiefly line of the Clan Livingstone (which is actually an Argyll clan, known in Gaelic as MacLea, or MacOnLea, or even Mac Donnsleibhe, with nothing to do with the place in Lothian) has been checked by testing some of the kits closest to the chief and his late father. Results were positive. The Clan has a reputation as one of the oldest in Argyll.
(Of course as with any such SNP/STR correspondence there can be a result out of the blue which shows a slight difference in the definition of the two sets on a twig somewhere. Being certain is always relative.)