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Genética Molecular em Análises Clinicas. TÉCNICAS DE AMPLIFICAÇÃO DE ÁCIDOS NUCLEICOS. Técnicas de amplificação de ácidos nucleicos. PCR Real Time PCR NASBA/TMA. PCR. OPTIMIZAÇÃO DO PCR. [MgCl 2 ] Th [dNTP] [primers] [DNA] [inibidores]. Variações. RT-PCR Multiplex PCR Nested PCR.
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Genética Molecular em Análises Clinicas TÉCNICAS DE AMPLIFICAÇÃO DE ÁCIDOS NUCLEICOS Prof.Doutor José Cabeda
Técnicas de amplificação de ácidos nucleicos • PCR • Real Time PCR • NASBA/TMA
OPTIMIZAÇÃO DO PCR • [MgCl2] • Th • [dNTP] • [primers] • [DNA] • [inibidores]
Variações • RT-PCR • Multiplex PCR • Nested PCR
Técnicas de amplificação de ácidos nucleicos • PCR • Real Time PCR • NASBA/TMA
Principio de funcionamento do Real-Time PCR Prof.Doutor José Cabeda
Químicas Utilizáveis Prof.Doutor José Cabeda
3’ 5’ SG SG SG SG SG Excitation 3’ 5’ SYBR-Green I
3’ 5’ SG SG SG SG SG Excitation Emission 3’ 5’ SYBR-Green I
Sybr-Green Detection • Intercalates to dsDNA • Inhibits DNA amplification so concentration is critical • Detects specific and non-specific targets • Low starting background with large increase in signal • Can run a melt curve to look at product specificity
3’ 5’ R Q Q R Excitation Excitation R Q R Q 3’ 5’ 3’ 3’ 5’ 5’ Sequence specific probes: Dual labeled probes
DabCyl FAM 10mer 25mer Molecular Beacons I
Excitation R Q Q Emission R Q R Molecular Beacons II X
Excitation R Q Q Emission R Q R Molecular Beacons II X
Molecular Beacons III • Can be used to quantitation and mutation detection • Need beacons for the normal and mutation sequence • Design is difficult due to nature of folding structure • Expensive when compared to FRET
Transfer Excitation Emission Hyb-ProbesTM Oligo 1: Fluorescein Oligo 2: Quencher Prof.Doutor José Cabeda
5’ 3’ Quenched FRET analysis • Two labeled probes, FAM at the 5’ and BH1 on the 3’ • When the probes hybridize the FAM energy is quenched by the BH1 • After the product is amplified run a melt curve to determine genotype • Different melt points are seen for normal and mutation
MGB MGB F F F F F Q Q Q Q Quimicas utilizáveis:sondas Eclipse
Aplicações Quantificação Prof.Doutor José Cabeda
Aplicações Detecção de Mutações / SNP Prof.Doutor José Cabeda
Aplicações Multiplex Detection Prof.Doutor José Cabeda
Os equipamentos Prof.Doutor José Cabeda
Rotorgene • The samples spin continually during a run at 500 rpm • The samples are heated and cooled in a low mass air oven • Tubes are illuminated as they pass the detector • On data acquisition energy is averaged over 20 revolutions to give the fluorescence of each sample • Four Channels • Ch1: ex 470nm, det 510nm • Ch2: ex 530nm, det 550nm • Ch3: ex 585nm, det 610nm • Ch4: ex 625nm, det 660nm
Técnicas de amplificação de ácidos nucleicos • PCR • Real Time PCR • NASBA/TMA
Amplification: schematic diagram Primer 1 Legend: Reverse Transcriptase • sense RNA • antisense RNA • sense DNA • antisense DNA RNase H Primer 2 Reverse Transcriptase T7 RNA polymerase Primer 2 Reverse Transcriptase Reverse Transcriptase RNase H Primer 1
Técnicas de amplificação de Sinal • bDNA (Quantiplex)