Two question about represent sequence in DADA2

General Discussion
1

Hello, I have two questions to confirm.

    1. First question

When I used qiime dada2 denoise-single (DADA2) to obtain the 'rep-seqs.qza' file， I found that each represent sequences in "Feature Detail" is identified by a unique ASCII code.

I used the same database to analyze different data, will the ASCII identity will be changed? I also made some attempts and found that ASCII code didn't change, so I want to
confirm whether the ASCII code will change or not ?

    1. Second question

The second question just like the first one, will this ASCII change when I use a different database? Such as comparing the same data to SILVA138 and Greengenes databases.

1 Like
2

Hi!

Each sequence ID is created based on the sequence itself, so the same sequence will always create the same ID.

Taxonomy annotations are based on the sequence itself and do not influence sequence ID. However, taxonomy annotations of the same sequence may vary between databases.

So if the sequence is the same, it will have the same ID but taxonomy annotation is not guaranteed to be the same if different databases were used.

Best,

4 Likes
3

Thank you very much!
This answer is exactly what I want!
Rain jie