In order to provide its customers with the large set of human full-length cDNA clones, OriGene has developed a high-throughput, quality control (QC) assessment of over 800,000 5-end sequenced clones within its archives. This QC was designed to make the large clone collection available to the research community, while at the same time maintaining strict qualifications for each clone included.
To qualify for inclusion on the list, the 5' read must align with the reference upstream of the initiation codon. Bias is given to those clones whose 5' read actually contains the ATG. This automated process is followed by a manual verification of the 3'-read and insert size, thereby completing the QC process. The last step includes an updated search of the public reference databases to look for new sequence versions.
Before a clone is shipped, it must pass three strict criteria,
1) the 5'-end read must align upstream of the initiation codon.
2) the 3'-end read must align downstream of the termination codon.
3) the insert must be the appropriate size with respect to the sequence alignment to the indicated reference.
As “investigational tools”, OriGene TrueClones may differ from the reference by acceptable single-nucleotide polymorphisms at the published rate of ~0.1%. All cDNA libraries were generated using reverse transcriptase and without PCR amplification, thus having a low error rate. Even with the assumption that the annotated sequence in the public database is correct, which does not have to be, it remains impossible to distinguish between naturally occurring polymorphisms and mutations from unintentional errors that may exist in any molecular clone. It has to be recognized that, in using these molecular clones, there are some inherent uncertainties and, hence, each should be viewed as a product for discovery. In many cases, OriGene has a second independently derived clone of the same gene that has similarly been confirmed for its 5’ and 3’ sequences, as well as for its approximate insert size.
Our molecular clone sequence data has been matched to the accession number below as a point of reference. Note that the complete sequence of our molecular clones may differ from the sequence published for this corresponding accession number, e.g., by representing an alternative RNA splicing form or single nucleotide polymorphism (SNP).
OriGene is dedicated to complete the full-length sequence of each clone, thereby making the 3 criteria listed above unnecessary. For these clones, the ORF of the reference must be included within the insert sequence. Should a sequence diverge from the reference ORF, a variant report is created and the clone is offered and indicated to be such a variant. Since all clones are derived from authentic cDNA libraries, each difference is likely to have some biological significance. It is for this reason, that OriGene is working hard to collect, verify, annotate and make available all the variants (both splice variants and SNP variants) for each gene. You will need to keep checking your favorite gene of interest to look for these variants as they become offered, or you can contact customer service to inquire about those that may be in the pipeline.
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