Gene expression profiling reveals sequential changes in gastric tubular adenoma and carcinoma in situ

Table 1 Amplification efficiency of formalin-fixed tissues.

Sample	AmplificationMethod	Starting materials		Amplified RNA(ng)	3Amplification Fold (X)
		Total RNA (ng) (1mRNA)	2Cell number
Fresh MKN45			690	152.2	761 X
	4T7 IVT only	20 (0.2)
SNU484			650	213.2	1066 X
Fixed MKN45			830	121.6	608 X
	T7 IVT only	20 (0.2)
SNU484			1090	128.6	643 X
MKN45			830	42120	210600 X
	5PCR-T7 IVT	20 (0.2)
SNU484			1090	45016	225080 X

RNAs from fresh and formalin-fixed xenograft tumors of MKN45 and SNU484 cells were amplified under the same conditions as described in the Materials and Methods.

¹mRNA : estimated to be 1/100 of total RNA (ng). ²Cell number: estimated number of cells from tissue sections required to obtain the starting RNA (20ng). ³Amplification folds: aRNA/estimated starting mRNA.

⁴T7 IVT: in vitro transcription using T7 RNA polymerase.

⁵PCR-T7 IVT: 20 cycles of PCR followed by T7 IVT.