If you use UG labs...Read!
There is a lot of traffic here, and a lot of questions on UG labs. So, this is an appropriate place for this.
If you use UG lab made gear, I strongly suggest that before you use the product, you peel the labels off the vials and hold them up to the light and look closely for foreign particles.
I have always done this out of paranoia. And it is a good thing. I have a vial from a very well respected and used UG source, and it has 2 vary small pieces of thread like lent in the vial. It is not crystalization or anything like that. If I did not pull the labels off and look, it could have been bad.
I stongly urge you to do the same. You can soak the vials in some warm water, and the labels will peel off pretty easy. Then hold them up in some light and look closely.
I will NOT disclose the sources name to anyone, as it could look like I am just bashing. So, out of fairness, no names.