Hi All,
I have recently run an ATAC-seq library on PBMCs that came back with 82% reads mapping to E.coli and only 5% mapping to the human genome.
The sequencing run was overclustered but had decent %PF of 70, a good Q30 of over 90% and perfect alignment to spiked-in PhiX. Since we autoclave and filter sterilize our reagents and solutions, and also check under the microscope the progression of lysis just before tagmentation, is it possible that the source of E.coli DNA is carry-over from poor Tn5 transposase isolation? The transposase came from a kit we purchased from a certain company. Has anyone experienced this?
I have recently run an ATAC-seq library on PBMCs that came back with 82% reads mapping to E.coli and only 5% mapping to the human genome.
The sequencing run was overclustered but had decent %PF of 70, a good Q30 of over 90% and perfect alignment to spiked-in PhiX. Since we autoclave and filter sterilize our reagents and solutions, and also check under the microscope the progression of lysis just before tagmentation, is it possible that the source of E.coli DNA is carry-over from poor Tn5 transposase isolation? The transposase came from a kit we purchased from a certain company. Has anyone experienced this?