While I don't practice in PA, my experience is that labs will only test for what they've been asked to test. If there was no discussion of marijuana use, they likely will not have asked for testing beyond alcohol.
In either case, blood tests can be challenged on a number of grounds. They are not "bullet proof" evidence as many would suggest.
You should consult with a PA defense attorney as soon as possible. It may be possible for you to get an independent test conducted on your blood.
Best of luck.
I agree with the first answer.
In some states, such as WI, however, the blood will automatically be tested for all drugs if the BAC is less than a .08.
Again, you should consult with a local, experienced DUI attorney. You can find such an attorney through the National College of DUI Defense: www.ncdd.com.
Yes. In Pennsylvania they test for BAC as well as metabolates of controlled substances. Some counties contract out their testing to private labs the state police and other counties use the State Police lab but they generally test for the same things.