One Step Nucleic Acid Amplification (OSNA) - a new method for lymph node staging in colorectal carcinomas

Table 3 Results of discordant case investigation between OSNA and histology (H&E Staining and CK19 IHC

No.	Stage UICC	Histology		OSNA				qRT-PCR			Conclusion
		size	description	original run copies/μL	+/-	second run¹copies/μL	+/-	beta-actin +/-	CK19 +/-	CEA +/-
1	IV	8 mm	Macrometastasis, only in slice b, not d	<250	-	5470	++	+	+	+	Discordant Sample mix-up
2	III	m	Macrometastasis, calcified tissue	<250	-	0	-	+	+	-	Discordant Beta-actin and CK19 value near the cut-off level
3	IV	3 mm	Macrometastasis, only level 2	<250	-	<250	-	+	-	-	Tissue allocation bias
4	IIA	-	negative	540	+	<250	-	+	-	-	Discordant Low copy
5	IIA	-	negative	1300	+	<250	-	+	-	-	Discordant
6	IV		negative	1300	+	290	+	+	-	+	Tissue allocation bias
7	IIIA	3.5 mm	Positive with IHC in level 1	25000	++	53700	++	+	+	+	Tissue allocation bias
8	IB	-	negative	27000	++	<250	-	+	-	-	Discordant Sample mix-up

OSNA: ++: CK19 mRNA copies/μL higher than 5000, +:CK19 mRNA between 250 - 5000 copies/μL, -: CK 19 mRNA copies/μL less than 250, ¹The indicated copy number is the mean of three OSNA runs, QRT-PCR: +: positive, -: negative.

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