Among body fluids lood is relatively rich in DNA, despite the fact that it is found in the white cells (the red cells outnumber the white cells by about 800-1000 to one). I have never seen a study which tried to perform luminol and DNA tests on serial dilutions of blood, which would settle the matter. Therefore, any claims to the effect that luminol is more sensitive than DNA profiling are speculative. Nevertheless, I have never heard anyone make such a claim, except in this case. There are papers which show that it is quite possible to extract a DNA profile from a luminol-positive spot. Therefore, we know that it is possible to obtain DNA from luminol-positive stains.
If the pro-guilt version of the knife is to be believed, DNA profiling must have a lower limit of detection that is lower than TMB testing for blood, yet now we are to believe that the lower limit of detection for DNA is higher than it is for luminol? I am not buying it.