Where is your LINK? You need 2 here. 1 to explain the DNA process that you are discussing (unless you are a DNA expert, in which case you need to be verified) and 2 to backup your assertions regarding Madeleine's DNA.
Salem
Here's a couple about LCN DNA :
THE INTERNATIONAL JOURNAL OF EVIDENCE & PROOF
' In specific terms, three key consequences of amplifying LCN DNA which can lead to different DNA profiles being observed:
(a) allele drop-out may occur because one allele of a heterozygote locus can be preferentially amplified
(b) stutters may be preferentially analysedthese are sometimes known as false alleles; and
(c) the method is prone to sporadic contaminationamplifying alleles that are not associated with the crime stain or sample.'
___________________
Low Copy Number DNA profiles
"First, the number of Polymerase Chain Reaction (PCR)11 cycles has to be substantially increased to obtain LCN DNA profiles, which inevitably magnifies the risk of contamination and inaccurate results from stochastic effects, random statistical anomalies.12 Secondly, even if a DNA profile is accurately yielded, there are difficulties associated with the propositions and interpretations that can be drawn from LCN DNA results. Since LCN DNA profile can stem from the cells of a single touch by an unconnected innocent individual prior to the crime, a phenomenon commonly termed adventitious transference'
http://tinyurl.com/onal93z
And here's a couple specific to FSS :
" Dozens of serious criminal cases are to be urgently reviewed......The spotlight will be thrown on a number of high-profile cases, including the disappearance of Madeleine McCann."
The Crown Prosecution Service ordered the re-examination of cases and queried its reliability"
.....had led to the temporary suspension of the laboratorys accreditation by the United Kingdom Accreditation Service"
"The Association of Chief Police Officers also announced it was suspending its use of the method called "low copy number" DNA."
(The Daily Mail -21st Dec 2007)
"This led the Association of Chief Police Officers (ACPO) to advise all police forces in England and Wales to review cases where samples had failed to give a DNA profile
In addition, other Police Forces around the world are reviewing cases where LCN DNA profiling resulted in the successful prosecution of suspects."
en.wikipedia.org/wiki/Forensic_Science_Service