LondonJohn
Penultimate Amazing
- Joined
- May 12, 2010
- Messages
- 21,458
About 240 different things that are commonly found in households.
Generally, however the argument for guilt goes that luminol is more sensitive to blood than the TMB test, luminol can detect blood in concentrations as low as 1:5M (five million) whereas TMB tests are only good to about 1:1M. Thus if the sample was highly diluted it is possible to get a positive with the luminol test and not with the TMB test. Blood is detectable to the human eye only in concentrations greater than 1:10K, (ten thousand) thus since these were invisible they were probably diluted to that extent.
This might be the next thing Harry Rag will be barfing throughout the ether, however it's yet another 'own goal' from the all-time master of the factual face-plant. Would you like me to tell you now what he's missing, or should we wait until he's scribbled it all over the comments sections of dozens of newspapers?
Just like ILE did as well, that's because the TMB test is more selective than luminol and a confirmatory test requires lab work to look at cells and/or crystals under the microscope.
It's not a confirmatory test, it's a presumptive one. There were no confirmatory tests ever reported so either they didn't bother to do one, or they didn't like the results and pretended they hadn't.
No, she's implying in her experience the TMB test is roughly twice as selective as applying luminol. Thus the TMB test eliminates about half the things that light up luminol.
Exactly. Standard practice is for confirmatory blood tests, such as these described in the link below, to be performed where presumptive tests have indicated the potential presence of human blood.
http://www.nfstc.org/pdi/Subject02/pdi_s02_m02_02_b.htm
There's simply no reason why such tests shouldn't/couldn't have been performed on the footprints, along with DNA testing, to show that human blood was present, and to identify the origin of that blood. There should have been more than enough material present to perform such tests.
