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"A question of Life or Death" - differentiating between healthy and apoptotic cells

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Dead or Alive on the ZE5™ - Using flow cytometry to measure apoptosis

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Easy-to-use Nuclear Staining Dye

Use Bio-Rad's PureBlu Hoechst 33342 Dye for routine nuclear staining in Cell Imaging applications and Fluorescence Microscopy. It is available as a ready-to-reconstitute, highly pure powder form, with only one dilution step required to obtain a ready-to-use solution.

Hoechst 33342 is a well-characterized blue-emitting fluorescent compound widely used for nuclear staining. As a DNA minor groove binding compound, it can permeate cell membranes therefore preferentially stain nuclei (Figure 1).

Fig. 1. Hoechst 33342 (in blue) binding dsDNA.

Figure 1. Hoechst 33342 (in blue) binding dsDNA.

Hoechst 33342 Spectra

The excitation and emission wavelength of PureBlu Hoechst 33342 Dye when bound to double stranded DNA are shown in Fig 2. The Stokes shift between excitation and emission wavelengths is large making it an excellent choice for nuclear counterstaining in Immunofluorescence Microscopy, especially when spectral separation is required to reduce fluorescence overlap.

Fig. 2. Hoechst 33342 excitation and emission spectra. Maximal excitation at 350nm (blue) and maximal emission at 461nm (red)

Figure 2. Hoechst 33342 excitation and emission spectra. Maximal excitation at 350 nm (blue) and maximal emission at 461 nm (red)

Preferred choice for unfixed samples

Use PureBlu Hoechst 33342 Nuclear Staining Dye with fixed and unfixed cells. It has increased permeability toward intact cell membranes when compared to DAPI and therefore is preferred when using unfixed samples.

To determine cell viability we also offer the non membrane permeable DNA-binding cell staining dyes Readidrop 7-AAD and Readidrop propidium iodide, in ready-to-use formulations and fixable VivaFix™ Cell Viability Assays in a range of excitation and emission spectra to enable easy incorporation into multi-color Flow Cytometry panels.