....well.. I will never win a prize for creative of the year, but I think that if you have to explain it, it's not ideal.... Like ladies fashion
So how about something very simple. The Lab Courier? Something like that. You don't even need a tagline, as everyone can see what you're about immediately. And there is a labcourier.com but not a lab-courier.co.uk...yet.
And if I type lab courier into google there isn't a single company with that in its name.
I also like Lab Logistics! Rolls off the tongue easily. LLS and similar acronyms are OK, the only thing is they get lost amongst all the other LLS's out there on the web.
I hope that helps a bit...