scholarly journals The normalization of gene expression data in melanoma: Investigating the use of glyceraldehyde 3-phosphate dehydrogenase and 18S ribosomal RNA as internal reference genes for quantitative real-time PCR

2008 ◽  
Vol 380 (1) ◽  
pp. 137-139 ◽  
Author(s):  
Orsolya Giricz ◽  
Janelle L. Lauer-Fields ◽  
Gregg B. Fields
2010 ◽  
Vol 5 ◽  
pp. BMI.S5596 ◽  
Author(s):  
Yi-Hong Zhou ◽  
Vinay R. Raj ◽  
Eric Siegel ◽  
Liping Yu

In the last decade, genome-wide gene expression data has been collected from a large number of cancer specimens. In many studies utilizing either microarray-based or knowledge-based gene expression profiling, both the validation of candidate genes and the identification and inclusion of biomarkers in prognosis-modeling has employed real-time quantitative PCR on reverse transcribed mRNA (qRT-PCR) because of its inherent sensitivity and quantitative nature. In qRT-PCR data analysis, an internal reference gene is used to normalize the variation in input sample quantity. The relative quantification method used in current real-time qRT-PCR analysis fails to ensure data comparability pivotal in identification of prognostic biomarkers. By employing an absolute qRT-PCR system that uses a single standard for marker and reference genes (SSMR) to achieve absolute quantification, we showed that the normalized gene expression data is comparable and independent of variations in the quantities of sample as well as the standard used for generating standard curves. We compared two sets of normalized gene expression data with same histological diagnosis of brain tumor from two labs using relative and absolute real-time qRT-PCR. Base-10 logarithms of the gene expression ratio relative to ACTB were evaluated for statistical equivalence between tumors processed by two different labs. The results showed an approximate comparability for normalized gene expression quantified using a SSMR-based qRT-PCR. Incomparable results were seen for the gene expression data using relative real-time qRT-PCR, due to inequality in molar concentration of two standards for marker and reference genes. Overall results show that SSMR-based real-time qRT-PCR ensures comparability of gene expression data much needed in establishment of prognostic/predictive models for cancer patients–-a process that requires large sample sizes by combining independent sets of data.


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Ana Érika Inácio Gomes ◽  
Leonardo Prado Stuchi ◽  
Nathália Maria Gonçalves Siqueira ◽  
João Batista Henrique ◽  
Renato Vicentini ◽  
...  

Genome ◽  
2018 ◽  
Vol 61 (5) ◽  
pp. 349-358 ◽  
Author(s):  
Yanchun You ◽  
Miao Xie ◽  
Liette Vasseur ◽  
Minsheng You

Gene expression analysis provides important clues regarding gene functions, and quantitative real-time PCR (qRT-PCR) is a widely used method in gene expression studies. Reference genes are essential for normalizing and accurately assessing gene expression. In the present study, 16 candidate reference genes (ACTB, CyPA, EF1-α, GAPDH, HSP90, NDPk, RPL13a, RPL18, RPL19, RPL32, RPL4, RPL8, RPS13, RPS4, α-TUB, and β-TUB) from Plutella xylostella were selected to evaluate gene expression stability across different experimental conditions using five statistical algorithms (geNorm, NormFinder, Delta Ct, BestKeeper, and RefFinder). The results suggest that different reference genes or combinations of reference genes are suitable for normalization in gene expression studies of P. xylostella according to the different developmental stages, strains, tissues, and insecticide treatments. Based on the given experimental sets, the most stable reference genes were RPS4 across different developmental stages, RPL8 across different strains and tissues, and EF1-α across different insecticide treatments. A comprehensive and systematic assessment of potential reference genes for gene expression normalization is essential for post-genomic functional research in P. xylostella, a notorious pest with worldwide distribution and a high capacity to adapt and develop resistance to insecticides.


Gene Reports ◽  
2019 ◽  
Vol 14 ◽  
pp. 94-99 ◽  
Author(s):  
Zhongdian Dong ◽  
Pushun Chen ◽  
Ning Zhang ◽  
Shunkai Huang ◽  
Hairui Zhang ◽  
...  

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