DAPI staining

Fig-3 Fluorescence microscopy of Blastocystis revealing MitoTracker Green uptake of MLOs with DAPI colocalization. The MLOs are situated very close to the nucleus (large DAPI-stained structures) and are clustered at opposite poles of the cell... 

DAPI is the fluorochrome of choice when dealing with small intraspedfic differences in maize. DAPI binds to both A-T and G-C base pairs and fluoresces when bound to either type. However, the fluorescence when DAPI is bound to A-T-rich DNA is greater than when bound to G-C-rich DNA. Comparisons of DAPI-stained nuclei to Feulgen-stained nuclei have demonstrated that this base pair specificity does not preclude the use of DAPI in detecting small DNA differences in maize.5... 

The number of 5-cyano-2,3-ditotyl tetrazolium chloride (CTC)-reducing bacteria were determined by using a final concentration of 2.5 mM and incubating the sample at 2°C for 2 h (Rodriguez et al. 1992). The reaction was stopped with 40% buffered formaldehyde (final concentration 2%). The samples were further filtered, DAPI stained and observed as described above. 

FIGURE 39.1. The three cell layers of the cornea. Shown on the left is a frozen section of an adult rabbit cornea stained with hematoxylin and eosin. On the right is a frozen section of a 6 week old mouse cornea. The mouse cornea is not fully mature until 8 weeks after birth. The left half visualizes the cornea by phase contrast microscopy. The right half shows the nuclei by DAPI staining. The density of the cells in the epithelial layer, and the paucity of keratocytes in the stromal layer are clearly seen with the nuclear stain. 

Results after microscopy are expressed as the ratio between total number of positive nuclei (BrdU staining) and total number of nuclei (DAPI staining) counted in 10 or more randomly selected fields, averaged on the number of replicates per each experimental point. This kind of analysis thus allows to express a proliferative index for the cell population. Results after ELISA detection are simply expressed as o.d. values, vs. an untreated control. A calibration curve can be prepared, to correlate the acmal o.d. readings with the number of cells per well, so that cell numbers can be extrapolated on the linear portion of the curve. 

The phytoplasma detection relied for more than last three decades on DAPI staining or electron microscopy. However, in the last 15 years the applications of DNA-based technology allowed to preliminary distinguish different molecular clusters inside these prokaryotes. The Phytoplasma Working Team of the International Research Project for Comparative... 

Most of the phytoplasmas infecting medicinal plants were characterized on the basis of symptoms, DAPI staining, electron microscopy, PCR/RFLP analysis and phylogenetic relatedness. 

Fig. 3 Hepatocyte polarity in different culture conditions, (a) Confocal microscopy reveals formation of bile cana-liculi (white arrows) in primary mouse hepatocytes. These structures are formed within 24 h when hepatocytes are cultivated between two layers of soft gel collagen (i.e., sandwich culture S) but not in monolayer confluent (Mc) or monolayer subconfluent (Ms) cultures. Green fluorescence corresponds to DPPIV staining (a marker for bile canaliculi). Nuclei appear blue (DAPI staining), (b) Bile canaliculi lumen is further revealed in z-stack confocal imaging in sandwich-cultured hepatocytes. Red corresponds to F-actin and green to DPPIV. Co-localization of the two markers is seen in yellow and corresponds to bile canaliculi. Nuclei appear blue (DAPI staining)...

Fig. 4 Confocal laser scans of human hepatocyte spheroids, (a) Human hepatocyte spheroid. Nuclei appear blue (DAPI staining). Bile canaliculi are visualized by green fluorescence (staining of the bile canalicular marker DPPIV). (b) Similar spheroid as shown in (a), with inclusion of sinusoidal endothelial cells (red) into the hanging drop culture. The endothelial cells do not form vessel-like structures as in vivo but build an epithelium at the surface of the spheroid, (c) Kupffer cells integrated into a spheroid of hepatocytes. (d) Reconstructed bile canalicular network of a spheroid of human hepatocytes. (e) Bile canalicular network of liver tissue...

Figure 5.10 (a, d) Fluorescence images (using intensities of DNA-specific bands of the cells DAPI stain) of the chromatin distribution of shown in (a) and (d) (c, f) Distribution of the HeLa cells in metaphase (a) and anaphase Raman intensities of protein bands of the (d). The cell in (a) measures ca. 25pm cells shown in (a) and (d). 

Phalloidin-DAPI Staining of Embryos 1. Phalloidin-Rhodamine or Phalloidin-Fluorescein (Invitrogen, Molecular Probes, Carlsbad, CA) 6.6 J.M stock solution diluted 1 500 in PBTA (freshly diluted and kept in the dark). 2. DAPI (Molecular Probes) 100pM stock solutions diluted 1 2,000 in PBTA (freshly diluted and kept in the dark). 

Eject the contents of each experimental needle using a 1-mL syringe filled with DAPI onto a microscope slide. The contents of each needle should be emptied with no more than about 100 pL of DAPI. Count the cells from each needle using a fluorescence microscope, counting all cells present within the drop by DAPI stain and/or other stains if cells are fluorescently labeled. 

Idiograms of chromosomes 1-4 and the sex chromosomes from the domestic fowl after chromo-mycin staining (GC-rich) and after Dapi staining (AT-rich) illustrate the reciprocal staining pattern obtained (Fig. 8.3). 

Fig. 3 A comparison of the image quality for a SIT video camera versus a cooled CCD camera. The sample is DAPI-stained, phenol-extracted bacteriophage T4 DNA. Images (top panels) and the intensity profile along the horizontal dotted lines (bottom panels) are shown for the SIT camera (a) and the cooled CCD camera (b). The intensities of single DNA molecules are indicated by the arrows in the bottom panels. The asterisk in lower panel b corresponds to a bundle of two DNA molecules. (Reproduced with permission from Hiraoka et al. (1987).)...

Fig. 1 Changes in the Xenopus sperm nuclei during incubation in Xenopus egg extracts. (A) DAPI-stained Xenopus sperm before incubation in an egg extract (B) after a 40-min incubation in an extract capable of NE assembly (C) 60 min after the addition of metaphase cytosol to sperm pronuclei formed in a cell-free extract. Scale bar, 10 pm.

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