Conditions favour long PCR products

[Dickens Lum]

Dear Netters,

        I'm now trying to isolate a single copy gene (2.1k bp) by PCR.
However, more than 30 copies of pseudogenes (600bp) exist in the genome
and they are preferentially amplified in the reaction. Designing primer
within the intron region is not possible as the sequence of the gene has
not been characterized.

        Is there any method that can help to amplify the larger PCR
product..?? Any PCR conditions that favour the amplification of longer
PCR product..??

        Thanks in advance...

Regards,
Lum