How do we know whether removing batch effects is required?

[hyjforesight]

Hello all,
I have 2 samples prepared from the same organ of the same mouse at the same time. One sample is tumor, the other is tumor-adjacent normal tissue. We prepared the libraries for these 2 samples at the same time and do sequencing on the same lane.
Do I need to remove the batch effects between these 2 samples?
Also, how could we visualize the batch effect before removing it?
Thanks!
Best,
YJ

[hyjforesight]

Just merge() 2 libraries and do UMAP. check whether the same cell clusters are localizing at different places. if yes, then it has batch effect.