Figure 4. Nuclease activity and specificity against ss- and dsDNA.

Relative activity of Northern shrimp nuclease on double stranded (ds) and heat denatured (ss) DNA as a function of divalent cations (A: magnesium alone, B: magnesium plus calsium) using the modified Kunitz assay. One hundred percent activity was set using dsDNA substrate at 5 mM MgCl₂. The ss nuclease-activity represents the relative activity on heat-denatured when compared to native ds calf thymus DNA. C displays relative activities of bovine pancreatic DNase I and P. borealis dsDNase on ssDNA in the described assay buffer or in a conventional Taq-buffer.