X files science Jay Mone

[Jay Mone']

Todd,
When the X files highlights technical procedures, it is always a 
subject of intense conversation in our department the next day.  The 
one episode to which you are referring was a doozy!
First, how might you determine that a protein in a sample is of alien 
origin?  Well, we know that all proteins on earth are different 
combinations of 21 different amino acids.  Si if you have a protein 
composed of amino acids which are different from the 21 known to be 
found in earthly proteins, you might be on to something.  Also, in 
higher organisms, all amino acids acids are of a specific type, namely 
what are called L-amino acids.  Some bacteria use D isomers, but it is 
unusal.  if your mystery protein was composed of D isomers, this would 
be quite startling.  One might also suspect that alien proteins would 
not display immunologic cross reactivity to earthly proteins;  that 
is, antibodies against earthly proteins would not react with alien 
ones.
Concerning the Southern that Scully did, we were all very impressed 
that she went from an unknown sample of DNA to a final autoradiogram 
result in 6 hours, and she looked damn good doing it (much to the 
consternation of a female molecular biologist in our department.  
Technically, you would need to isolate the unknown DNA, clone 
fragments into suitable vectors, and then sequence the fragments.  
using the sequences, you could then construct synthetic probes for use 
in both Southerns and PCR analysis.  This process normally takes 
several weeks at best, but then, we don't look as hot doing it either.

Jay Mone'
Millersville University