ICE Issue 9

31 The Israel Chemist and Chemical Engineer Issue 9 · January 2023 · Tevet 5783 History of Chemistry Articles producing DNA pure enough to get a meaningful result. In the case of ancient tissues, this is a prevailing problem and Gila’s recommendation was to send the samples to a lab specializing in ancient DNA sequencing. Genetic sequencing is done in Israel on modern DNA only, so the samples had to be sent abroad. This did not happen, so the issue was postponed for some time. Several years later, I saw on TV news a report that included an interview with Prof. Oded Rehavi of the Neurobiology Department in Tel Aviv University, in which it was mentioned that he deals with ancient DNA. Oded referred me to Prof. Christopher Mason of Cornell University, who collaborates with him and whose lab performs the DNA sequencing for him. Chris volunteered to run the DNA analysis of the chess pieces free of charge, but requested samples of bovine and human skin as a reference. There was no problem with bovine skin; I simply cut a piece out of one of my leather belts. Regarding human skin, I turned to my friend Prof. Juri Kopolovic, the head of the Pathology Department of Hadassah Ein Karem Hospital in Jerusalem. Juri explained that it is illegal to supply human samples, but generously offered to provide a piece of his own skin after some minor surgery he planned to undergo. In the meantime, I asked Chris why he needs references, as the human and bovine DNA sequences are known. Instead of replying, he referred me to a forensic lab in Texas, that specializes in ancient genome sequencing. The manager of the lab ruled out any possibility of performing DNA sequencing on skin that had been treated chemically. End of story; there was no need any more for Juri’s altruistic donation of his own skin. Oded Rehavi mentioned to me that there are works negating the conjecture that the infamous lampshades were made of human skin. A due search led me to Mark Jacobson’s book [1]. The book describes a lampshade found in the USA, whose DNA sequencing revealed human origin. Several years later, in repeated testing, human contamination of the sample was detected, and the lampshade was determined as being most probably made of parchment. This was published in 2012 in National Geographic’s TV movie Human Lampshade: A Holocaust Mystery. To my surprise, the program featured Prof. Chris Mason from Cornell with whom I had been in touch, as the scientist who performed both the original and the following corrective analysis. He testified that the correction was facilitated by advanced technology, that had improved between the analyses. Why then was it impossible to perform DNA sequencing of the tanned leather/skin of my chess set, while parents again received an apartment in which Germans had lived during the war. I have no idea whether my father purchased the chess set, or perhaps found it in one of the flats among the gadgets left behind by the Germans. I suppose he found it in one of the flats because, after the war, he could not possibly afford to purchase such an apparently expensive set. It is known that, during the Holocaust, the Nazis produced artifacts from bodies of Jews they murdered. They made not only soap from human fat, but also “ornamental” objects like lampshades, from human skin. There is no evidence of chess figurines made from human skin, but it could be possible. If so, my chess set should be in Yad Vashem, the Holocaust memorial museum in Jerusalem, and not in my private collection. It became crucial for me to pursue this issue thoroughly. When identifying compounds by searching a spectral library, it is most advisable not to depend on the computer blindly, but to compare the spectra visually. Inspecting the library spectra revealed that the IR spectra of bovine leather and human skin are almost identical, and that the probability that the chess pieces are made of processed bovine leather is just a few percent lower than that they are made of human skin. The expert opinion of Prof. Stephen Weiner from the Archeology Department of the Weizmann Institute of Science in Rehovot and of Dr. Michael Bradley fromThermo Scientific in Madison, Wisconsin, was that it is impossible to distinguish between human skin and bovine leather by means of IR spectroscopy. They both recommended solving the problem by DNA analysis. I turned to my friends in the forensic department of the Israeli Police. It was explained to me that the forensic lab in Jerusalem compares human DNAs, but does not have the ability to compare DNA of other species. I was referred to Dr. Gila Bar-Gal (no connection to my company Bargal Analytical Instruments) in the Faculty of Agriculture of the Hebrew University, who deals with the analysis of the origin of DNA. Gila was very responsive. Incidentally, at the same time, she was asked to check a horn smuggled from India, suspected to be ivory, and we could help her by using FTIR/ ATR to show that it was a plastic artifact. Gila’s staff used a polymerase chain reaction (PCR) replication technique and confirmed that the samples were of human origin. Gila used her remarkable scientific insight and compared the DNA of the chess pieces with that of her students. It was identical to one of them, indicating that they had contaminated the samples with their fingers. They resampled the chess figurines several times, but did not succeed in