106 copies of two dUMP-containing PCR amplicons were treated with or without UNG and then amplified by real-time PCR. UNG was from various suppliers, and real-time PCR was performed using the master mix from the QuantiTect Probe PCR +UNG Kit. ΔCT on the Y-axis indicates CT values for non-UNG-treated samples subtracted from CT values for UNG-treated samples. The UNG supplied with the QuantiTect Kit provided the greatest ΔCT (9-12 cycles). This indicates that QIAGEN UNG digests carryover PCR products more effectively than UNG from other suppliers.
The QuantiTect Probe PCR Kit overcomes the need for optimization of reaction conditions, which can be tedious and time-consuming. Simply add primers, probe, and cDNA template to the ready-to-use PCR master mix, and start the reaction on any real-time cycler (see also the table "Components of 2x QuantiTect Probe PCR Master Mix").
In comparison with other DNA polymerases, only HotStarTaq DNA Polymerase in combination with a unique buffer specifically amplified a 497 bp fragment (from 50 copies of an HIV-pol-gene construct in a background of 1 µg human genomic DNA). M: Markers.
Duplicate reactions were performed on the Mx3005P using tenfold dilutions of human keukocyte cDNA (10 ng to 0.01 ng) and a TaqMan assay for IL1R2 (a cytokine). The QuantiTect Probe PCR Kit provided accurate gene expression analysis from low to high template amounts with a PCR efficiency of 101%.
Probe-based real-time PCR with UNG pretreatment was carried out using the QuantiTect Probe PCR +UNG Kit. Reactions were run in duplicate on the ABI PRISM 7900 using 10-fold dilutions of human leukocyte cDNA (100 ng to 10 pg) and a TaqMan assay for IL8 (a cytokine). The amplification plots were evenly spaced, leading to a high PCR efficiency of 94%.
Tenfold serial dilutions of leukocyte cDNA (100 ng to 1 pg) were analyzed in duplicate on the Mx3005 using the QuantiTect Probe PCR Kit with primers and a FAM-labeled probe specific for IL8 (interleukin 8). A PCR efficiency of 97% over 6 logs of template dilution was achieved, and as little as 1 pg of IL8 transcript was sensitively detected.