Difference between read and contig based taxonomic classification

Question

[BAGeno]

Hi,

I want to understand the difference between read based and contig based classification. What is the methodology behind these two? Which is more accurate?

Answer 1

[Sej Modha]

Read based taxonomic classification is where each read generated from a sequencing method is search against a database of known sequences to find similarity. Contig are longer sequences generated by stitching overlapping reads. Contig based classification is where these longer sequences are search against known sequences to identify similarity and label them taxonomically. For both cases a number of different tools can be used to search against a set of databases. Some examples of such tools are: RiboPicker, BLAST, DIAMOND