Table A2.

Average blank signals versus QC pool enzyme activities (μmol/L/h).

	GAA		IDUA
Laboratory	Blank Signal Average	A QC Pool Average	Blank Signal Average	A QC Pool Average
A	0.59	0.65	0.19	0.23
B	0.00	0.05	0.08	0.15
C	0.00	0.13	0.00	0.08
* D	0.17	0.75	0.23	1.86
* E	0.01	0.67	0.35	1.62
* F	1.57	1.29	2.19	1.98
G	0.01	0.19	0.00	0.13
* H	0.18	0.85	0.23	1.61
I	0.00	0.20	0.00	0.19
J	0.02	0.05	0.07	0.15
TN (K)	0.06	0.07	0.00	0.03
* L	0.92	0.21	1.61	1.82

* Laboratories using DMF.