lambda won't cut

[Donald W. Back]

In article <9209091448.AA23264 at server.uga.edu> mcgraw%gandal.dnet at SERVER.UGA.EDU writes:



>Hello netters,

>A colleague provided us with some lambda clone DNAs "purified" from plate
>lysates.  They won't cut with EcoR1.  We tried further purification with
>additional phenol/chloroform extractions.  The uncut DNA looks good on a
>gel, and the OD's are good.  The inserts should cut out with EcoR1 based on
>the way the library was made (R1 linkers).  We haven't worked with lambda
>in quite a while, but I imagine that some of you out there are cutting
>yours successfully as you read this.

>What do you suggest?

>                                Mike Grosse
>                                McGraw lab
>                                University of Georgia

I've experience similar problems on occassion. One of two methods will
get around the problem. Either treat the DNA with proteinase K and phenol 
extract or add NH4Ac to 2.5M, 15 min on ice, centrifuge the ETOH ppt the 
supernatant.