No, it was definitively identified as Meredith's DNA profile in the e-gram. How that profile got there is what's in question.
That Stefanoni thinks some DNA can hide in a scratch on a knife is laughable. That would provide as much protection as hunkering down in a fox hole 1 inch deep. No DNA could have survived a cleaning that removed every trace of blood. It's impossible.
But that aside, you've still not addressed the list of issues I posted above, each of which invalidates the results or the claim that the knife was the murder weapon.
And you can add to that list the fact that of the 30 alleles in the profile, 22 were below the 50 RFU threshold, and one was missing entirely. Only 6 alleles were over 50, and only one of those was over 100, barely. This is far to faint a trace to consider reliable, and very typical of what would be expected of lab contamination. That's on top of all the other issues with the knife.
And then there's the issue with the negative control showing contamination as Numbers pointed out, but now I feel like I'm piling on.
Yes, all indications are that the alleged DNA of Kercher on the knife blade was the result of contamination, probably occurring in Stefanoni's lab - she had used a suction device to concentrate the sample from the knife blade, a potential mechanism for contamination.
Here's a document listing the many issues from Stefanoni's lab work and testimony that I prepared a little more than 10 years ago (7 May 2015) with some help from some persons highly knowledgeable in the area of DNA testing. It may be a useful summary.
In the summary I indicate that several of the issues were violations of the European Convention of Human Rights; this should be understood as my identification of violations that were likely to have been found by the ECHR if Knox and Sollecito had been finally convicted of the murder/rape of Kercher and Knox and/or Sollecito had lodged with the ECHR an application claiming those violations against Italy as part of that miscarriage of justice. Of course, Knox and Sollecito had been finally acquitted of the murder/rape charges by the Marasca CSC panel in 2015, so the ECHR would not have an opportunity to rule that the impugned actions constituted violations of the Convention.
The Seventeen-Plus Forensic Science Sins of Patrizia Stefanoni
There was a pattern of misconduct and malpractice by Patrizia Stefanoni and the Italian Scientific Police in their forensic investigation of the murder and rape of Meredith Kercher, and the trials of Amanda Knox and Raffaele Sollecito, who were charged with those crimes.
The pattern of misconduct and malpractice included investigations in Patrizia Stefanoni's laboratory, the treatment of evidence, and her court testimony. She ignored and violated numerous essential technical standards for forensic science investigation, violated fundamental standards of ethical behavior, and produced invalid conclusions that contradicted logic and well-known scientific principles.
Stefanoni's misconduct and malpractice resulted in violations of the European Convention of Human Rights, Article 6, right to a fair trial, by Italy, including but not necessarily limited to, the failure to provide adequate time and facilities for the preparation of the defense (Art. 6.3b) and the failure to provide equality of arms to the defense (Art. 6.1).
Here is a summary.
1. Stefanoni failed - indeed, refused repeated requests - to turn over a copy of the best evidence of the DNA profiling investigation, the raw data, called electronic data files (EDFs), to the defense;
2. She suppressed numerous results, including potential exculpatory findings; these include blood stains from the downstairs flat, the full results of the rape kit, and results of tests on the putative semen stain on the pillow;
3. She destroyed evidence, in particular the bra clasp, preventing any DNA profile retest;
4. She entered false reports of data into her reports (RTIGF #1 & #2);
5. She committed perjury, for example, regarding the amount of DNA in the knife blade sample and that RT-PCR was used to quantify that DNA;
6. She delayed providing the minimal DNA data that was given to the defense until late in the trial;
7. She did not reveal in a timely manner to the defense and the court that TMB tests were done and precluded the presence of blood in the luminol footprint hits attributed to Amanda Knox;
8. She and her forensic police team mishandled specimen collection, in particular by swabbing large areas, failing to change gloves, failing to use DNA-free forceps for holding specimens, and by handling DNA specimens with dirty gloves;
9. She and her forensic police team mishandled chain-of-custody, specifically by repackaging the knife from Sollecito's kitchen in a police station without proper control against contamination;
10. She repeated tests that were conducted in secret (as deduced from irregularities in test sample numbering), to obtain false inculpatory results, for the kitchen knife and bra clasp;
11. She apparently manipulated positive control samples in the RT-PCR quantification to obtain high intercept levels probably in order to make unknown DNA samples appear more highly concentrated than they truly were;
12. She used the Qubit fluorometer to quantify DNA concentration in samples without having validated the equipment and procedure;
13. She arbitrarily used certain specimens registering "too low" for DNA concentration on the Qubit fluorometer for DNA profiling, and apparently not others, in a suspect-centered manner, violating good forensic practice. A reading of "too low" with the Qubit may mean there is actually no DNA present;
14. She attempted to conduct LCN DNA profiling in a method she had "invented" without validating the method;
15. She attempted to conduct LCN DNA profiling in a lab not adequately set up to prevent contamination, and thus inherently unsuited for LCN DNA profiling, which is highly sensitive to low concentrations of DNA;
16. She stated in court testimony that she had never been told of a contamination incident in her lab, however, the data she gave to the defense shows several incidents of contamination;
17. She did not supply records of methodology and quality control (such as rate of contamination and corrective measures) nor provide profiles of blank and positive control specimens to the defense, such records and control profiles are ordinarily and necessarily part of a report from a forensic DNA profiling lab;
18. She did not call out all the DNA alleles and profiles detectable on the bra clasp, instead only identifying the victim and one of the suspects (Sollecito), while DNA from several other males was detectable (indicating that the bra clasp had been contaminated).
19. She presented conclusions from the DNA data contrary to reasonable forensic science practice because of the absence of replication and the presence of contamination.
Only YOU would call Peter Gill, PhD, Professor Emeritus of Forensic Genetics, Forensic Genetics Research Group, Oslo University Hospital, Norway a "tinpot FOAK scientist"!
Oh yeah, I forgot, Knox was wearing that incredibly pristine white skirt next morning. No sign of any blood there, M'Lud! 
