For LZ,
sunnyday's desalting method is the best to try. I will be surprised if it
doesn't work. I guess you have to use a syringe because nobody likes to
inject 32P into their FPLC. In that case, you should be careful of the
fraction size. Don't mix two well separated peaks during fractionation.
kaka1000's vivapure spin column离子交换柱 is a cation/anion exchange column,
to which unlimited volume can be loaded. In the end, elute with B buffer.
The peak is sharp because the salt concentration is high and all protein
will rush out. Theoretically, it can concentrate the target protein a lot
folds. Therefore, it is a great method for concentrating small stuff (e.g. a
peptide) that can't be concentrated easily.