Injecting into integrated strains

[sarafi at BINAH.CC.BRANDEIS.EDU]

Hi!  I am having trouble getting transformants when injecting single
cosmids at 40ng/ul into a strain carrying an already integrated array (for
a GFP marker in this case).  My co-injection marker was rol-6 in this
case, but we have also had this trouble with other
plasmids and different integrated strains.  Also, in transformed lines
that I do sometimes get, the array seems to be lost quite quickly---after
about two or three generations...Has anyone else had this problem with
injections into strains carrying integrated arrays?  Does anyone have an
explanation or a solution?  Thank you very much.
Trina Sarafi
(Sengupta lab)