I am performing lysosome tracker experiment using HUVEC cells. I am treating cells with Rapamycin  in the presence and absence of an inhibitor of lysosome acidity. In the group treated with RAPA and the inhibitor, I am always getting a huge red dot as you can see in the attached figure. Any idea what it can be? Is that huge dot appearing as result of fusion between lysosome and autophagosome without degradation due to the lack of acid milieu.  

If so how we can explain that since lysotracker is working only in acid compartment. 

Thanks

Modar