Table IV.

Storage Condition on QC Sample Stability. Back-Calculated Concentration Values (pg/mL) of QC Samples Kept at Room Temperature (RT), −4, −20, or −80°C

	Validation Range, pg/mL		24 h@RT		24 h@4oC		2 weeks@-20oC		4 months@-80oC
	High value	Low value	pg/mL	%CV	pg/mL	%CV	pg/mL	%CV	pg/mL	%CV
LLOQ	49	153	NT		NT		86	9.4	NT
LQC	412	600	447	2	482	3.4	504	3.3	474	1.3
MQC	1142	1784	1483	1.4	1478	1.1	1513	3.9	1464	0.7
HQC	4148	6150	5224	1.3	5198	2.9	5154	7.1	5180	1.8

The qc range from assay validation studies is included in each table. Results shown as mean concentration value and %CV (n = 2)

NT not tested