After testing out the use of long (34cm) gels with copper plates attached to evenly distribute heat the search continued for a method of achieving high resolution more quickly.  A solution came in the way of  Spreadex^® Polymer NAB from Elchrom Scientific.

Spreadex^® Polymer NAB is a product that is added to standard non-denaturing TAE polyacrylamide gels.  It allows production of gels to use in electrophoresis equipment that a lab already owns, rather than having to purchase new equipment and buy pre-cast gels.  Instructions for pouring gels (the methods I used) were available at one time, however, all gels are sold pre-made at this point (2003).

Below are gels comparing the resolution achieved and the time necessary to obtain it.  Description of gel composition and running conditions are given beneath each picture.  The samples to compare between them are labeled as: 11, 53, 96, 120

15% polyacrylamide run for 22 hours (6 hours at 200V and 16 hours at 80V) on a 16cm gel.
 

15% polyacrylamide run for 34 hours at a constant 6W on a 32cm gel with upper and lower buffer chambers and copper sheets clamped to the glass plates to evenly distribute heat.
 

15% polyacrylamide run for 13 hours at a constant 24W on a 32cm gel with upper and lower buffer chambers and copper sheets clamped to the glass plates to evenly distribute heat.
 

7% polyacrylamide with Spreadex^® Polymer NAB run for 3 hours at 300V on a 16cm gel.

Greater separation (twice the distance between the top two bands of the 25bp molecular weight ladder - 300/275) was obtained from the Spreadex gel after running for 5 hours.  The bands pictured above had only traveled about halfway down the gel.  (Gel aparatus used was a Hoefer SE 600 Series Standard Vertical Gel Unit.)

Following the guidance provided in the product instructions shorter DNA fragments may be resolved using lower concentration gels that run faster.  For visualization of DNA from 100-200bp a 5% gel is typically run from 1.5-2 hours at 300V on a 16cm gel made using 0.5mm thick spacers and comb.  (See below . . .)

5% polyacrylamide with Spreadex^® Polymer NAB run for 1 hour 45 minutes at 300V on a 0.5mm thick 16cm long gel.
 
 
 

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