Cacodylate & CoCl2

[Marie Helene DURRENS MPI]

Chris

Back in the bad old days (1981!!) of tailing cDNA & plasmid for library 
production I saw a similar thing.

It was easily circumvented by passing the tailed cDNA or vector through 
a Sephadex G50 spin column prior to the next step - suggesting that one 
or more of the low molecular weight components was responsible for the 
pellet

I suggest that you desalt your reaction using any one of 20 or so 
commercial colums, kits, etc, before attempting to precipitate it