Increasing number of nonchimeric reads compared to the number of input reads

[Abdelrahim-maker]

Hi everyone

I was using dada2 in R on my arbuscular mycorrhizal fungi reads and I noticed that after truncating them, I got an increased number of nonchimeric reads compared to the input I had. for example my input for one of the samples was 666 reads and the nonchim is 47,000. another sample has an input of 8 and nonchim which is 49 reads. How is that possible?

Thanks

[benjjneb]

It's not possible. How are you arriving at this result?