IV Quality Filter System (Q-Filter) Help

A quality filter for nucleotide sequences.


IV Q-Filter: A quality filter system of influenza virus nucleotide sequences.
Aim: Since most of the nucleotide sequences in public databases are from direct submission, they are not very consistent. The sequences are either incomplete or with some annotation errors. Since the data quality is of crucial importance for successive data analysis, there is a growing need to corroborate the data in order to analyze them effectively. The IV Q-Filter is developed to classify and rank the IV data into 7 categories according to sequence consistency: C1-C4 and P1-P3, as illustrated below.

C1: Complete CDS                          

Example: Accession Number AB027494

C2: 5'UTR+complete CDS              

Example: Accession Number AJ404627

C3: 3'UTR+complete CDS              

Example: Accession Number AB212649

C4: 5'UTR+complete CDS+3'UTR 

Example: Accession Number AX350198

P1: Partial CDS                                

Example: Accession Number AY590561

P2: 5'UTR+partial CDS                   

Example: Accession Number K01023

P3: 3'UTR+partial CDS                   

Example: Accession Number K00961

If a nucleotide sequence contains multiple CDS regions, each of these regions will be evaluated separately. The classification of the whole sequence will be combination of all its sub-region categories.

Example: Accession Number DQ107515 will be classified as P3,P1 because its first CDS region belongs to P3 category and its second CDS region belongs to P1.

UTR Search and Download:

This section offer UTR search and download and the search condition is the same as the Main Search.


IVDB is supported by institutional grant from Beijing Institute of Genomics, CAS  Feedback