Determining the optimal reference gene, Determining the optimal reference gene 7 – Bio-Rad SsoAdvanced™ Universal Probes Supermix User Manual
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SsoAdvanced
™
Universal Probes Supermix Instruction Manual
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Real-Time PCR Validation for Gene Expression Experiments
The following validation experiments are critical for obtaining valid and publishable real-time
PCR data following the MIQE guidelines. These simple-to-follow experiments should be
completed prior to starting a new real-time PCR project.
Determining the Optimal Reference Gene
To properly perform a gene expression experiment, it is imperative that an optimal
reference gene(s) is used. The reference gene(s) must maintain a consistent expression
level across all samples in the project regardless of treatment, source, or extraction
method. The variation in reference gene expression is somewhat dependent on the level
of fold change discrimination desired. For example, if a twofold change in expression is
important, then the reference gene should have little to no variation in expression. However,
if a 20-fold change in expression is important, then the reference gene expression can have
some variability. To validate a reference gene(s), follow the steps on the next page.
1. Begin searching for a candidate list of reference genes by searching publications, speaking
with researchers using similar model systems, and mining microarray data, if available.
Minimally, five reference genes should be selected for evaluation. For your convenience,
Bio-Rad offers pre-plated reference gene panels using our highly validated and optimized
.
Table 2. Thermal cycling protocol.
Amplification
Polymerase
Annealing/
Setting/Scan Activation and
Denaturation Extension + Plate
Real-Time PCR System
Mode
DNA Denaturation at 95/98°C
Read at 60°C** Cycles
Bio-Rad
®
CFX96
™
, CFX384
™
,
CFX96 Touch
™
, CFX384 Touch
™
, All channels
10–30 sec
CFX Connect
™
Bio-Rad
®
iQ
™
5, MiniOpticon
™
,
Standard
15–30 sec
Chromo4
™
, MyiQ
™
ABI 7500, StepOne,
Fast
5–15 sec
10–30 sec 35–40
StepOnePlus, 7900HT
Standard
60 sec
and ViiA7
Roche LightCycler 480
Fast
10–30 sec
Standard
60 sec
Qiagen Rotor-Gene and
Fast
10–30 sec
Stratagene Mx series
* 2–3 min denaturation at 95°C is highly recommended for genomic DNA template to ensure complete denaturation.
** Shorter annealing/extension times (1–10 sec) can be used for amplicons <100 bp. Longer annealing/extension
times (30–60 sec or more) can be used for amplicons >250 bp, GC- or AT-rich targets, low expressing targets,
crude samples, or for higher input amounts (for example, 100 ng of cDNA or 500 ng of genomic DNA).
30 sec at 95°C for
cDNA
or
5–15 sec
2–3 min at 95°C
for genomic DNA*
35–40