Last data update: 2014.03.03

R: Gene expression from real-time quantitative PCR
qpcrR Documentation

Gene expression from real-time quantitative PCR

Description

Gene expression levels from real-time quantitative polymerase chain reaction (qPCR) experiments on two different plant lines. Each line was used for 7 experiments each with 45 cycles.

Format

A data frame with 630 observations on the following 4 variables.

flour numeric Fluorescence level
line factor Plant lines rnt (mutant) and wt (wildtype)
cycle numeric Cycle number for the experiment
transcript factor Transcript used for the different runs

Source

Data provided by Kirsten Jorgensen <kij@life.ku.dk>.
Added by Claus Ekstrom <ekstrom@life.ku.dk>

References

Morant, M. et al. (2010). Metabolomic, Transcriptional, Hormonal and Signaling Cross-Talk in Superroot2. Molecular Plant. 3, p.192–211.

Examples


data(qpcr)

#
# Analyze a single run for the wt line, transcript 1
#
run1 <- subset(qpcr, transcript==1 & line=="wt")

model <- nls(flour ~ fmax/(1+exp(-(cycle-c)/b))+fb,
             start=list(c=25, b=1, fmax=100, fb=0), data=run1)

print(model)

plot(run1$cycle, run1$flour, xlab="Cycle", ylab="Fluorescence")
lines(run1$cycle, predict(model))

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

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> library(MESS)
Loading required package: geepack

Attaching package: 'MESS'

The following object is masked from 'package:stats':

    power.t.test

> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/MESS/qpcr.Rd_%03d_medium.png", width=480, height=480)
> ### Name: qpcr
> ### Title: Gene expression from real-time quantitative PCR
> ### Aliases: qpcr
> ### Keywords: datasets
> 
> ### ** Examples
> 
> 
> data(qpcr)
> 
> #
> # Analyze a single run for the wt line, transcript 1
> #
> run1 <- subset(qpcr, transcript==1 & line=="wt")
> 
> model <- nls(flour ~ fmax/(1+exp(-(cycle-c)/b))+fb,
+              start=list(c=25, b=1, fmax=100, fb=0), data=run1)
> 
> print(model)
Nonlinear regression model
  model: flour ~ fmax/(1 + exp(-(cycle - c)/b)) + fb
   data: run1
      c       b    fmax      fb 
29.5932  0.8406 96.7559  3.7226 
 residual sum-of-squares: 53.79

Number of iterations to convergence: 9 
Achieved convergence tolerance: 7.746e-06
> 
> plot(run1$cycle, run1$flour, xlab="Cycle", ylab="Fluorescence")
> lines(run1$cycle, predict(model))
> 
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>