In article <1994Jul7.155930.11658 at leeds.ac.uk> futers at biovax.leeds.ac.uk
>In article <2vh39l$k3r at mserv1.dl.ac.uk>, (David Johnston) daj <daj at nhm.ac.uk> writes:
>>On Thu, 7 Jul 1994 13:03:27 GMT,
>> BRIAN PETER MERRY writes:
>>>We need some help. We're running 1% and 2% gels in our lab using Lambda hin3
>>>as a molecular weight marker. We load 500 ng of lambda in our marker lane and
>>>we don't get resolution of the 500 bp band when prestaining the gel with etbr.
>>>Do we need more DNA in the marker lane? More etbr (we now use 2ul/50ml of
>>>gel, this used to be enough). Any comments/suggestions will be appreciated.
>>If my memory serves me correctly, the 564 base fragment and the 23130 base
>>fragment contain the 2 cos sites/sticky ends of the phage DNA and anneal
>>together. Heat marker to 65C for 5 mins and cool rapidly on ice before
>>loading to dissassociate the 2 fragments.
>It is the 23130 and the 4361 bands that have the cos sites. The 564 band is
>weak due to being small. If you need to have a size reference around 500, I
>would suggest using a different marker such as the 100bp ladder.
> Simon Futers (futers at biovax.leeds.ac.uk)
This is only tangential to the above discussion, but I'd like to mention that
HindIII+EcoRI doubly digested lambda makes a very nice molecular weight marker
for < 5000 bp fragments.
HindIII lambda is 23130 + 9416 + 6557 + 4361+ 2322 + 2027 + 564 + 125 bp.
HindIII+EcoRI lambda is 23130 + 5148 + 4973 + 4268 + 3530 + 2027 + 1904 + 1584
+ 1375 + 947 + 831 + 564 + 125 bp.
Having the 1584/1375 bp and 947/831 bp pairs is quite useful.
Institute for Molecular Biology and Biophysics
ETH-Honggerberg (Swiss Federal Institute of Technology)
8093 Zurich, Switzerland
email: tan at aeolus.vmsmail.ethz.ch