While our analysis does not exclude the possibility that the CPC98 mtDNA genome sequence has been contaminated with a modern haplogroup P sequence, this scenario seems unlikely given the extremely low frequency of this haplogroup in modern samples [6], [8], [14], [16], [17].
Unfortunately, synthetic oligonucleotides are often contaminated with a significant fraction of truncated failure sequences, makes the product purification process difficult.
Typically, crude products from solid-support organic synthesis are contaminated with a significant fraction of highly homologous failure sequences that arise from incomplete detritylation, coupling, sulfurization, capping or deprotection [21].
(Raw certified milk) is a product that can be contaminated with a toxic waste ( S. dublin ) or intermittently contaminated.
It is not clear to us why streptophyte sequences were present in our acantharean dataset, but one possible explanation could be that the samples were contaminated with a small amount of pollen.
The lanyards were contaminated with an amount of tritium 26 times that of the allowable level.
Of the 2,027 non-primate trace archives, 454 (22.39%) were identified as contaminated with human sequence (Table S1B).
5.5% of the reads were possibly contaminated with adapter sequence and 1.72% of the reads mapped to the human genome.
Using a primate specific SINE, AluY, we screened 2,749 non-primate public databases from NCBI, Ensembl, JGI, and UCSC and have found 492 to be contaminated with human sequence.
