Table 2

Correlation of RNA degradation time with capillary electrophoresis features and mRNA quantities

RNA feature

Predominant size of

RNA detected and

amplicon length

(for mRNA only)

0 to 18 hours comparison

p values

0 to 24 hours comparison

p values

0 to 96 hours comparison

p values

Combined comparison

p values


18S % of total area (n = 53)

1700 bp

0.001***

0.001***

0.001***

0.001***


28S % of total area (n = 53)

3770 bp

0.001***

0.001***

0.001***

0.001***


5S % of total area (n = 53)

160 bp

0.043**

0.001***

0.386

0.001***


Fast region % of total area (n = 53)

____

0.717

0.92

0.001***

0.001***


Inter-peak region % of total area (n = 53)

____

0.001***

0.001***

0.001***

0.001***


Post region % of total area (n = 53)

____

0.36

0.16

0.316

0.42


Lower Marker % of total area (n = 53)

____

0.256

0.322

0.072*

0.001***


Small fragmentation region % of total area (n = 53)

____

0.12

0.046**

0.074*

0.026**


28S:18S ratio (n = 53)

____

0.553

0.082*

0.001***

0.001***


RQI

____

0.223

0.024**

0.001***

0.001***


DNMT1 mRNA (au) (n = 41)

5084 bp – 142 bp

0.173

0.006**

0.004**

0.001***


FMR1ex.3.4 mRNA (au) (n = 43)

4350 bp – 122 bp

0.265

0.001***

0.001***

0.003**


FMR1ex13.14 mRNA (au) (n = 43)

4350 bp – 89 bp

0.024**

0.013**

0.012**

0.001***


GUS mRNA (au) (n = 52)

2200 bp – 80 bp

0.169

0.001***

0.001***

0.001***


B2M mRNA (au) (n = 35)

976 bp – 114 bpo

0.093*

0.13

0.571

0.01**


GAPDH mRNA (au) (n = 52)

1310 bp – 110 bp

0.117

0.001***

0.001***

0.001***


*Generalized estimating equations (GEE) were used. Data from samples with different levels of total RNA degradation (early, moderate, high) are shown as the p-values of the chi square test (p < 0.1*; p < 0.05**; p < 0.001***) and the sample size (n).

Godler et al. BMC Clinical Pathology 2009 9:5   doi:10.1186/1472-6890-9-5

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