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Order & InquiryTel: (713)732-2181 Fax: +1-866-747-4781E-mail: [email protected]
Order & InquiryTel: +49-89-46148500 Fax: +49-89-461485022E-mail: [email protected]
2x Probe qPCR Master Mix
DescriptionBiotool™ 2x probe qPCR master mix utilizes a special performance-enhanced Taq DNA polymerase protected via a hot-start activation technique, and optimized qPCR buffer system to perform fluorescence labeled probe based quantitative PCR (qPCR). The mix, prepared at 2x reaction concentration, can be directly used for robust and low-template quantitative PCR with high sensitivity, specificity and reliability.
ContentsCat#:B21302
(200 rxns with 50 µL/rxn)Cat#:B21303
(1000 rxns with 50 µL/rxn)2x Probe qPCR Master Mixa
50x ROX Reference Dye 1(High Conc.)
50x ROX Reference Dye 2 (Low Conc.)
1.25 mL x 4
200 µL
200 µL
1.25 mL x 20
1000 µL
1000 µL
Contents Amount Per Reaction (µL)
Amount Per Reaction (µL) Final Concentration
2x Probe qPCR Master Mix
Template
Forward Primer (5 µM)
Reverse Primer (5 µM)
ROX Reference Dye
Distilled Water
Total Reaction Volume
25 10 1xVariable Variable 1 – 100 ng0.5 – 9 0.2 – 3.6
0.2 – 3.6 50 – 900 nM
50 – 900 nM
0.4 1x
0.5 – 9
Add to 50 Add to 20 -
-50 20
1
Step1 2
Temperature
Distilled Water
Total Reaction Volume
Hot-Start DNA Polymerase Activation PCR
HoldDenature Anneal / Extend
Cycle (40 cycles)
95 °C 60 °C
5 – 10 mins 15 secs 30 – 60 secs *
50 µL
95 °C
Do Not Use ROX Reference Dye
Use ROX Reference Dye 1 (High Conc.)
Use ROX Reference Dye 2 (Low Conc.)
Applied Biosystems7300/7900HT Real-Time PCR System,StepOnePlus™
Bio-Rad,Roche
Applied Biosystems 7500, 7500 Fast Real-Time PCR System, Stratagene MX3000P™
Components
Notice1. Repetitive freeze-thaw cycles should be avoided while using.2. Please select appropriate ROX according to the Real-time PCR instrument used as follows:
* Extension time may be adjusted according to the qPCR instruments used. For example, the extension time should be set to no less than 30 seconds when using ABI 7700 and 7900HT, 31 seconds when using ABI 7000 and 7300, 34 seconds when using ABI 7500, or 10 seconds when using ABI StepOnePlusTM.
2. Data Analysis1). Relative quantitation: Target gene expression is measured against an internal standard.
1. Guidance for qPCR Amplification1). To obtain reliable quantitative PCR reaction results, it is recommended to run three replicates for each sample with reaction volume of 50 µL / well. The suggested template amount is 10 to100 ng for genomic DNA or 1 to 10 ng for cDNA template. The following loading table is designed for reaction volume of both 50 µl and 20 µl.
Note:• 200 nM of primer final concentration is applicable for most cases. The concentration can be adjusted within 50 - 900 nM when amplification efficiency is not satisfactory.• Too much or too little template used may lead to inaccuracy of quantitative result. A range of 1 - 100 ng is recommended to result in a good Ct value (15 < Ct < 35). If template is stocked at high concentration, dilute it prior to loading to prevent possible loading errors.• It is recommended that the amplicon length should be within the range of 100 - 500 bp, with 100 -200 bp preferred.• The concentration of probe can be adjusted between 50 -250 nM.
2). Perform quantitative PCR using optimized cycling conditions. Provided below is a standard two-step program shown in which annealing / extension step is combined at 60°C (Step 2). Please note that the hot-start polymerase in this system needs to be activated at 95°C for 5 minutes prior to amplification (Step 1). If the amplicon sequence is GC-rich, the time for pre-denaturation / enzyme activation (Step 1) can be prolonged to 10 minutes. Standard Two-Step Amplification Program:
Storage• All reagents should be stored at -20 °C.
a. Contains hot-start DNA polymerase, dNTPs and Mg2+
Protocol
Order & InquiryTel: (713)732-2181 Fax: +1-866-747-4781E-mail: [email protected]
Order & InquiryTel: +49-89-46148500 Fax: +49-89-461485022E-mail: [email protected]
Gene expression can be measured by the quantitation of cDNA converted from a messenger RNA corresponding to this gene relative to a calibrator sample serving as a physiological reference. In a typical experiment, gene expression levels are studied as a function of either a treatment of cells in culture, of patients, or of tissue type. The calibrator sample in each case is the cDNA from either the untreated cells or patients, or a specific tissue type. All quantitations are also normalized to an endogenous control such as 18S rRNA to account for variability in the initial concentration and quality of the total RNA and in the conversion efficiency of the reverse transcription reaction.
Set CtA1 as the Ct value of the target gene of sample 1, and CtB1 as the Ct value of the internal control gene of sample 1; Set CtA2 as the Ct value of the target gene of sample 2, and CtB2 as the Ct value of the internal control gene of sample 2. The expression difference (in fold) of the target gene in sample 1 and in sample 2 can be calculated this way (2-∆∆Ct approach):
∆∆Ct = (CtA2 - CtB2) - (CtA1-CtB1)
The expression level of the target gene in sample 2 is 2-∆∆Ct times that of sample 1.Note:This calculation method is based on the assumption that the amplification efficiency is 100% (the amount of products after each cycle is doubled). If the amplification efficiency is not 100%, the calculation formula needs to be amended according to actual reaction efficiency. For example: if the amplification efficiency of the target gene and internal control genes is 1.90, then the formula should be amended into 1.90-∆∆Ct.
2). Absolute quantitation: Compares the Ct of an unknown sample against a standard curve with known copy numbers.Absolute quantitation is applicable only if isolation procedure and sample contents do not effect PCR amplification. The quantitation of genomic DNA may lend itself for absolute quantitation against a standard curve.
No amplification plot
Cycling number is insufficient
Check if there is signal collection procedure
during cycling
Generally the cycling number is set to be 40. But notice that too
many cycles will result in excessive background, thereby
reducing the reliability of the data.
Check if the primers are degraded
In two-step program, signal collection is usually positioned at annealing and extension stage; for three-step program, signal collection should be positioned
at 72 °C extension stage.
Test the integrity of primers after long-term storage through PAGE electrophoresis to confirm if the primers are degraded already.
Problem Potential Cause(s) Solution(s)
No amplification plot
Degradation of templates
The concentration of templates is too low
Prepare new templates and retry.
Low amplification efficiency
The concentration of templates is too low
Degradation of templates
The amplicon is too long
There are PCR inhibitors in the reaction
The reagents or waterused is contaminated
Appearance of primer dimer
Inaccurate pipetting volume
Difference in temperature control in different
wells of qPCR instrument
Too low template concentration
Change new reagents or water and retry. The reaction should
be set up in a superclean bench to minimize contamination
from aerosol.
It is normal where amplification occurs in negative control
after 35 cycles. Analysis can be performed combining
with the melt curve.
Use pipettor with better performance, elevate the
reaction volume, and dilute the templates to
increase the pipetting volume
The lower the template concentration, the worse
the repeatability. Decrease the dilution fold or increase
the volume of template used.
Regularly maintain the instruments.
They are usually brought in when adding templates. Increase the
dilution folds or prepare new templates and retry.
Reduce the dilution fold and retry. For target gene with unknown
expression level, begin without template dilution.
Ct value appears too late
Apparent amplification
can be observed in negative control.
Bad repeatability of experiment
Reduce the dilution fold and retry. For target gene with unknown
expression level, begin without template dilution.
Optimize the reaction. Try three-step program or
re-design the primers.
Prepare new templates and retry.
The length of the amplicon is recommended to be within 100 bp-150 bp.
Problem Potential Cause(s) Solution(s)
Trouble Shooting
