Why barcode list doesn't filter exactly according to the same as list?

Question

[Info.shi]

Hi everyone,

I filter the BAM produced by 10x with a list of barcodes. But I did not get exactly the same barcode number after filtration i.e. Filtered. bam. I expected the exact same number of barcodes as I provided in the list to the filer bam file.

Kindly suggest to me if I am missing something.

Thank you.

[ATpoint]

What is the context? Which list, what and how did you filter? What does this number refer to?