Development of an Ammonium Sulfate DNA Extraction Method for Obtaining Amplifiable DNA in a Small Number of Cells and Its Application to Clinical Specimens

Table 3

Successful β-globin gene amplification frequency using DNA extracted from various numbers of PTC cells on archival smear slides using the three different methods.

No. of cells	A		B		C
	No. of β-globin amplification	P value*	No. of β-globin amplification	P value*	No. of β-globin amplification	P value*
25; (𝑛=10)	9	0.011	0	0.002	3	0.206
50; (𝑛=10)	9	0.011	3	0.206	4	0.527
100; (𝑛=10)	10	0.002	8	0.058	8	0.058
200; (𝑛=10)	10	0.002	8	0.058	8	0.058
500; (𝑛=10)	10	0.002	10	0.002	9	0.011
1000 (𝑛=10)	10	0.002	10	0.002	10	0.002

A: ammonium sulfate DNA extraction method; B: Pinpoint Slide DNA Isolation System; C: TaKaRa DEXPAT; PTC: papillary thyroid carcinoma. *Two-tailed Fisher's exact test.