Just you won't run in the same trouble as I did:
When multiplexing in 454 Titanium sequencing, using multiple MIDs, don't use both MID 16 and 18 in the same sequence run! When I did this, allowing for the standard 2 errors in MID calling, I had a significant amount of contamination from MID16 samples in MID 18 samples and visa versa. Fortunately when not allowing any MID errors at all, this problem was solved.
If this occurs in other MID combinations I don't know, but watch out!
When multiplexing in 454 Titanium sequencing, using multiple MIDs, don't use both MID 16 and 18 in the same sequence run! When I did this, allowing for the standard 2 errors in MID calling, I had a significant amount of contamination from MID16 samples in MID 18 samples and visa versa. Fortunately when not allowing any MID errors at all, this problem was solved.
If this occurs in other MID combinations I don't know, but watch out!