Parameters 

Appearance: Orange red liquid 

Abs = 464 nm (before photolysis) 

Abs/Em: 510/610 nm (after photocrosslinking to nucleic acid) 

Molecular Weight: 511

Storage 

Store at -20°C and protect from light. When stored as directed, product is stable for at least 12 months.

Description 

PMA is a high-affinity DNA-binding dye that itself has weak fluorescence but binds to nucleic acids to emit brighter fluorescence. It has a high affinity especially for double-stranded DNA. PMA does not penetrate the cell membrane and therefore can only selectively label exposed DNA on dead cells. This property allows PMA to be widely used for screening of pathogenic cells that can be cultured by means of real-time quantitative PCR (qPCR) because PMA can bind strongly to DNA on dead cells and cannot be used for amplification of PCR reactions(figure 1). This property of PMA allows it to be widely used for the screening of pathogenic bacteria that can be cultured by means of real-time quantitative PCR (Fig. 2)

Figure 1. Principle of quantifying live and dead bacteria by qPCR after PMA modified DNA

Figure 2. Using the DNA of live and heat-inactivated E. coli. as a template, after adding PMA, qPCR reaction was carried out to monitor the effect of PMA on the reaction. The primers were designed with 16S rRNA as template. (A) Amplification curve obtained by real-time quantitative PCR reaction after adding PMA; (B) PMA was added to the DNA of dead and live E. coli., qPCR reaction was performed, and the obtained Δ Ct value was compared with the negative control (Ct added to PMA - Ct without PMA).

Notes 

1. The conditions of the label vary depending on the cell type. Before each experiment, determine the optimal conditions. The above methods are for reference only. 

2. The length of the amplified fragment is generally shorter than 100 bp. When the amplified fragment is larger than 100 bp, the signal of the heat-inactivated PMA-added cells will be weakened. 

3. When preparing a positive control, usually 1 ng of live cell genomic DNA is sufficient to obtain good signal values. Therefore, when extracting genomic DNA using a commercial extraction kit, it is recommended to use 1-2 μL of DNA eluent as a starting point for optimization. 

4. There are quenching problems with fluorescent dyes. Please avoid light to slow down the fluorescence quenching. 

5. For your safety and health, please wear lab coats and disposable gloves

  UE-P4051