Table 2: Comparison of DNA yield and purity extracted using three different methods from various numbers of PTC cells on archival smear slide.

No. of cellsExtraction method DNA concentration (ng/μL) Total DNA yield (ng) Purity A260/A280P value*

25
( )
A0.013 ± 0.0020.652 ± 0.0811.6 ± 0.1 P = 0.001
B0.001 ± 0.0010.070 ± 0.0411.0 ± 0.0
C0.004 ± 0.0020.190 ± 0.1221.4 ± 0.2

50
( )
A0.059 ± 0.0072.975 ± 0.3371.7 ± 0.2P = 0.000
B0.007 ± 0.0030.327 ± 0.1751.2 ± 0.1
C0.017 ± 0.0060.834 ± 0.2771.3 ± 0.2

100
( )
A0.104 ± 0.0085.184 ± 0.3881.5 ± 0.2P = 0.001
B0.056 ± 0.0072.777 ± 0.3561.6 ± 0.2
C0.085 ± 0.0064.241 ± 0.2911.6 ± 0.3

200
( )
A0.179 ± 0.0088.947 ± 0.4131.6 ± 0.2P = 0.000
B0.075 ± 0.0113.745 ± 0.5501.8 ± 0.3
C0.136 ± 0.0166.797 ± 0.8121.4 ± 0.2

500
( )
A0.291 ± 0.01514.560 ± 0.7411.8 ± 0.1P = 0.000
B0.139 ± 0.0176.941 ± 0.8711.6 ± 0.0
C0.190 ± 0.0159.486 ± 0.7321.7 ± 0.1

1000
( )
A0.406 ± 0.00920.280 ± 0.4571.7 ± 0.0P = 0.020
B0.242 ± 0.05212.115 ± 2.5851.8 ± 0.1
C0.307 ± 0.05215.347 ± 2.6231.6 ± 0.1

A: ammonium sulfate DNA extraction method; B: Pinpoint Slide DNA Isolation System; C: TaKaRa DEXPAT; PTC: papillary thyroid carcinoma.
Analysis of variance.
Mean value ± standard deviation.