PstI digest failure

[Roland Hübner]

Greetings Sally,

 have a look at the NEB cat, p. 231, Table: "Average Fragment Size 
generated by Endonuclease Cleavage"... Although Pst I is not listed, 
compare the entries for Sac I that are given for 3 different bacterial 
genomes and you will notice that you can have an 8-fold reduction in 
mean fragment size depending on the organism you are working with...
Thusly, perhaps Pst I is cutting your "plant" DNA (!)

 Back to the bench, I would check whether Nsi I is cutting  ;^)

Roland