Returned mail: User unknown (fwd)

John Stiles stiles at uhunix.uhcc.Hawaii.Edu
Wed Jun 15 14:10:11 EST 1994

In article <Pine.3.87.9406142051.B24186-0100000 at csuvax1> obrien at CSUVAX1.MURDOCH.EDU.AU (Philip OBrien) writes:
>---------- Forwarded message ----------
>Date: Tue, 14 Jun 1994 19:58:00 +0800 (WST)
>From: Philip OBrien <obrien at csuvax1>
>To: methodsandreagents at
>Subject: Returned mail: User unknown (fwd)
>---------- Forwarded message ----------
>Date: Tue, 14 Jun 94 19:54:55 +0800
>From: Mail Delivery Subsystem <MAILER-DAEMON at csuvax1>
>To: postmaster at csuvax1, obrien at csuvax1
>Subject: Returned mail: User unknown
>   ----- Transcript of session follows -----
>550 methods-and at csuvax1... User unknown
>   ----- Unsent message follows -----
>Received: by (5.65/1.34)
>	id AA24084; Tue, 14 Jun 94 19:54:55 +0800
>Date: Tue, 14 Jun 1994 19:45:50 +0800 (WST)
>From: Philip OBrien <obrien at csuvax1>
>To: methods-and at csuvax1
>Message-Id: <Pine.3.87.9406141950.A23910-0100000 at csuvax1>
>Mime-Version: 1.0
>Content-Type: TEXT/PLAIN; charset=US-ASCII
>Dear netters
>In order to clone pectic enzyme genes from fungi we have identified 
>conserved regions within the genes (from amino acid sequences)and want to 
>make PCR primers from these regions.  However we have to cope with 
>2-4fold degeneracy at each codon (there are 6 codons/conserved region).  
>Although we can make the primers how does this level of degeneracy affect 
>the efficiency of PCR?  Are we likely to get to many non specific 
>products?  I would be interested to hear from anyone with experience of 
>this method.
>Phil O'Brien
>BES, Murdoch University,
>Murdoch WA 6150 AUSTRALIA
>email: obrien at

	We've done a bit of this and the rule of thumb seems to be keep the degeneracy to about 512 fold for best results. I have to admitt that I have violated this a bet and it still worked.

John Stiles
stiles at

More information about the Methods mailing list