using gelatin for PCR - gelatin for PCR (Nov/07/2005 )

is it possible to use the gelatin that we routinely use for microbiological medias? as much as i can understand there are two possible problems-
1. contamination- this can be taken care of by autoclaving at 15 pounds once
2. ions - what if we try treating the gealtin post autoclaving with chelex 100 slurry? would that be able to remove the ions from the gelatin solution?
3. enzymes- will a single autoclaving suffice? or else we can repeat the autoclaving after chelex treatment.
4. will two cycles of autoclaving affect the quality of gelatin and in such a situation we can do the chelex treatment before autoclaving?
please do give in whatever suggestions you can give....

Fish gelatin was originally used in PCR reactions as a bulking agent. See the Sigma catalog. It has been left out of most PCR reactions for many years because it interferes with DNA sequencing gels.

Agar or agarose (not gelatin) is used in microbiological media.