Frequently asked questions
General
- Why are immunoglobulin and T cell receptor genes described as "genes", instead of "gene segments" or "segments"?
- Why are abbreviations of IG and TR used, instead of Ig and TcR?
- Why are immunoglobulin and T cell receptors in "subgroups", rather than in "families"?
- Why is there sometimes capitalization in midsentence?
- Is it judicious to use a L-PART1 oligonucleotide to amplify V-REGIONs?
- Where can I find known human IG allotype sequences?
- What differences between allotypes and alleles?
- Why are there differences in the V and J assignments of rearranged human IG and TR sequences, between IMGT/LIGM-DB and the generalist databases GenBank/EMBL/DDBJ, although the flat file accesssion numbers are identical?
- Is it possible to observe sequences with additional amino acids in the CDR-IMGT?
- Is it possible to selectively obtain, from IMGT/LIGM-DB, the sequences of antibodies that are known to bind to antibodies?
- Where, on the IMGT site, can we find information about the antibody diversity calculation?
- Is it possible to get restriction maps for the IG and TR loci?
- Which gene to choose, in IMGT/V-QUEST results, when two genes give an identical score?
- How to analyse comparison between IG V sequences from a species with human ones?
- How to determine the CDR3-IMGT length of a germline V gene?
- How to represent CDR-IMGT lengths?
- What are the recommendations for correctly representing V-REGION IMGT Protein displays?
- Where can I find information about the antibody diversity calculation with clear figures and legends?
- Is it possible to retrieve flanking sequence at the 5' and/or 3' ends of IMGT labels that describe IMGT/GENE-DB annotated sequences?
- What are "P" nucleotides in a V-J or V-D-J junction?
- How are the CDR lengths defined in IMGT?
- What are the differences between IgBlast and IMGT/V-QUEST?
- Is the IMGT gene name valid for both genomic and cDNA sequences?
- When do we use "V-ALPHA" or "V-BETA"?
- How the V-ALPHA and V-BETA of rearranged cDNA sequences, amino acid sequences, protein 2D and 3D structures should be referred to?
- Is it possible to study rearrangements of a pseudogene or unusual sequences (such as translocated IG with other genes)?
- How to find the correspondence between a "previous" gene name and the current IMGT gene name?
- What defines an allele?
- Is it possible to identify IMGT/LIGM-DB sequences associated to a PubMed abstract?
- How to summarize the fact that the FR-IMGT and CDR-IMGT delimitations represent the standard for FR and CDR?
- Are the IMGT gene names the official ones?
- How can I retrieve the V leader sequences from IMGT reference sequences?
- Does IMGT allow one to make multiple alignments and derive consensus sequences?
- How are the positions of gaps and insertions placed in IMGT Collier de Perles?
- Is it possible to search an amino acid sequence against the IMGT reference directory?
- How to find IMGT unique numbering for a VH or VL protein domain?
- How to obtain IMGT/LIGM-DB entries while querying PubMed?
- Is there information on the frequency and population use of particular V, D and J genes?
- How is delimited the CDR3?
- How can one appropriately and clearly number amino acids in the constant region of immunoglobulins, for example the LL of IgG1 in position 4 and 5 of CH2 (...APELLGGP...)?
- How to find cDNA or rearranged gDNA using a given human or mouse V gene?
- Why "Protein displays" and "Colliers de Perles" of variable genes do not include the last strand G?
- How to retrieve the recombination signals (RS) from the IMGT databases?
- How to find the hinge sequences of IG heavy chains of many species easily?
- How to retrieve IGHC hinge sequences?
- Why is the delimitation of IGKJ2 given as 1094-1132 in V00777 from IMGT/LIGM DB, whereas it is 1096-1134 found from the literature source?
- How to obtain from IMGT/GENE-DB complete amino acid sequences (artificially spliced) of a constant gene, or of a group of C genes?
- How can I get the sequences of the recombination signals?
- What does the letter 'S' mean in the temporary IMGT gene nomenclature, for example in IGHV1S1 or IGHJ1S1 ?
- What are the functionalities of rearranged V-(D)-J genes compared to germline V, D or J genes?
- How to deal with 'complement' sequences?
- In 'Alignments of alleles' why is the first nucleotide of the exons in 'pink' color?
- How to propose new IG or TR gene names to IMGT?
- Does "partial in 3' " or "partial in 5' " make sequences non-functional or is it just that the gene region was not fully sequenced?
- There are a few sequences that are marked "F" but end in a stop codon. Are these functional?
- What does 'OR9' means in some Homo sapiens TRBV genes?
- What happens if there is a stop codon in a leader sequence?
- How to retrieve nucleotide sequence of IG and/or TR genes without any introns?
- Are nucleotide sequence differences in the untranslated EX4 taken into account in the assignment of the TRAC and TRDC alleles?