earth gate iris

[Ollock]

Well, if you only allowed through the DNA. However, you would only be identiying the person by their DNA. Obviously this would alsobe smart enough to know approximatley how much DNA, was in the person, so a Goa'uld could simply rip out a chunk of skin, and try to walk back through, and either way, that would only allow through the DNA of the eye, so the Goa'uld, or anyenemy for that matter, could not take your DNA and walk back through.

Owen Macri

/nitpick belated
Sorry, there is no such thing as 'DNA of the eye'. Every cell in your body has an identical copy of all 46 chromosomes (or whatever the number for the nonhumans.)
/end nitpick

[sparky]

If you wanted to stop a goa'uld coming through the stargate, perhaps it would be more feasible to use something like Thor's Hammer? I don't mean to knock the idea of selective re-materialization (it's quite cool) but would probably be more simpler to remove something bad after it comes through.... you know like radiation therapy or something that primarily targets cancers, except in this case it barbeques goa'uld.

Also, a problem may be that you accidentally kill a tok'ra (or a jaffa symbiote) that comes through the gate. The thing is if you could make an exception for tokra the goa'uld could probably replicate it etc.

Another counter-measure to preventing the materialization of a goa'uld could be genetically engineering every cell in a goa'uld to have some human DNA inside say a non-functional nucleus that would trick the detector screening for goa'uld into thinking the goa'uld was human... well sortof... .