Gel Spacing?

[tucker_a at umbsky.cc.umb.edu]

Dear Suzanne

I sounds like you are using ABI's recipe(from the users manual) to make
Long Ranger gels.  This could be your problem.  Long Ranger has a 
different
protocol.  You need a 5% LR gel, not 4% like the ABI book says.  
Mix 18 g Urea, 26 ml dH20, 5 ml LR sol't, and 5 ml 10XTBE for about 30 
minutes
Filter/Degas 5 minutes
Add 250 ul 10%APS and 35 ul TEMED
Swirl and pour

Longer Ranger doesn't need the ion exchange resin

If the spacing is too high(>12) you can decrease the amount of LR by 0.1 
ml
increments until the spacing in optimal.  

I recommend you give FMC a call.  They were very helpful to me.

Amy Tucker