Hi Vital
I have never marked unmated queens but I have marked and clipped queens
around thirty at a time sequentially, using the method shown on
http://website.lineone.net/~dave.cushman/clipmark.html
I did not wash my fingers between queens and I do not recall any problems.
The mating nucs contain small frames that are of such a size that the total
frame area is about equal to one langstroth deep frame. with 1000 -1500
bees.
I would be wary of using larger nucs in this fashion as the queen pheramone
(weak in a very young queen) would be spread too thinly among the larger
number of bees.
Regards From:- Dave Cushman, G8MZY
Beekeeping and Bee Breeding, http://website.lineone.net/~dave.cushman
IBList Archives, http://website.lineone.net/~d.cushman