Table 1

Squared Correlation Coefficients Obtained for Commonly Used Assay Methods in the Divison of Clinical Chemistry,Department of Pathology,University of Pittsburgh Medical Center, Pittsburgh, September 1994

Analyte	R2	Low Conc	High Conc	Rank	Method	Class
Leutenizing Hormone	0.9854	50.1	255	1	IMX	NA
Albumin	0.9903	1.7	4.9	2	Ektachem	NA
Calcium	0.9922	5.0	13.5	3	Ektachem	NA
Digoxin	0.9970	0.3	4.0	4	TDX	A
Serum Uric Acid	.9974	1.1	12.4	5	Ektachem	A
Alpha Tocopherol	0.9975	2.3	9.4	6	HPLC	A
Sodium	0.9976	108	156	7	Ektachem	A
Disopyramide	0.9977	0.7	7.6	8	TDX	A
Procanamide	0.9978	1.8	18.6	9	TDX	A
Serum Amylase	0.9978	43.5	294	10	Ektachem	A
Magnesium	0.9979	0.6	5.6	11	Ektachem	A
Prolactin	0.9980	15.4	72.5	12	IMX	A
Total CPK	0.9982	106	937	13	Ektachem	A
Phenobarbital	0.9982	6.9	74.8	14	TDX	A
Serum Glucose	0.9983	45	431	15	Ektachem	A
Ethosuximide	0.9983	14.5	156	16	TDX	A
Serum Creatinine	0.9985	0.6	11.4	17	Ektachem	A
LDH	0.9985	31	543	18	Ektachem	A
Gentamycin	0.9986	1.0	8.9	19	TDX	A
Beta HCG1	0.9988	219	1044	20	IMX	A
Total Bilirubin	0.9988	0.2	24.2	21	Ektachem	A
Primidone	0.9989	2.5	22.5	22	TDX	A
Chloride	0.9989	75	121.5	23	Ektachem	A
Carbamazepine	0.9989	1.5	17	24	TDX	A
Triglycerides	0.9990	11.5	342	25	Cobas	A
ALT	0.9990	25	288	26	Ektachem	A
Phenytoin	0.9991	3.4	36.2	27	TDX	A
Quinidine	0.9991	0.8	7.8	28	TDX	A
Lidocaine	0.9991	0.0	9.1	29	TDX	A
Beta Carotene	0.9991	0.0	9.6	30	HPLC	A
NAPA	0.9991	0.0	28.4	31	TDX	A
Amikacin	0.9992	4.3	44.2	32	TDX	A
Total Protein	0.9992	3.9	9.9	33	Ektachem	A
Vancomycin	0.9994	0.0	93.5	34	TDX	A
Cholesterol	0.9994	6.0	403	35	Cobas	A
BUN	0.9994	8.0	86	36	Ektachem	A
Potassium	0.9995	1.8	9.2	37	Ektachem	A
Tobramycin	0.9995	0.0	11.2	38	TDX	A
Valproic Acid	0.9995	14.4	131	39	TDX	A
AFP	0.9996		11.6	280	IMX	A
Retinol	0.9996	0.0	2.7	41	HPLC	A
Theophylline	0.9996	3.3	35.8	42	TDX	A
Ethanol	0.9996	50	300	43	Cobas	A
Glucose (DT-60)	0.9997	30	239	44	DT-60	A
Acetominophen	0.9997	14	145	45	Cobas	A
Alkaline Phosphatase	0.9998	82.5	748	46	Ektachem	A
Phosphorus	0.9998	0.7	6.9	47	Ektachem	A
GGTP	0.9999	47.5	840	48	Ektachem	A
AST	0.9999	59.5	944	49	Ektachem	A
TSH	0.9999	0.1	92.6	50	IMX	A
Hb A1c	0.9999	4.3	24.1	51	HPLC	A