Labeling controls autofluorescence

Figure 6. A Photomicrograph (x 51,000) of caffeine treated leaf epidermal cell showing electron-dense deposits on cell wall and membrane vesicles fusing with the plasmalemma (arrows). B Immunofluorescence labeling of flavonoids in cell walls of leaf epidermal strips (arrows) and autofluorescent stomata (x 62.5). C Immunogold labeling of the walls of a mesophyll cell (left, x 41,000). Ch, chloroplast EC, epidermal cell G, Golgi IS, intercellular space MC, mesophyll cell (right, control x 19,500).

Fig. 9. Flow analysis of apoptotic human peripheral blood lymphocytes using direct TUNEL assay. Human peripheral blood lymphocytes (1 x 10 ) treated (A) without or (B) with dexamethasone (0.1 ijlM) for 16 h were transferred to a 15-ml tube. Paraformaldehyde (2%) was added to cells with shaking and incubated for 10-15 min in ice with occasional shaking. Cells were washed with PBS with 1% BSA and 3-4 ml cold acetone was then added to cells. After 2-3 min incubation on ice with occasional shaking, cells were washed twice and TUNEL reaction mixture including enzyme TdT and fluorescein-labeled anti-dUTP antibody was added to cells (H). For the negative control group, only label solution without TdT was added to cells ( ). Cells without any addition of reaction or label solution were used for assessment of the autofluorescence ( ). The cell mixture was incubated 1 h at 37°C in the dark. The result of the apoptosis after flow analysis was expressed as a histogram using software CellQuest (Becton Dickinson). In Fig. 9A Ml (nonapoptotic cells), 86% M2 (apoptotic cells), 14%. In Fig. 9B Ml (nonapoptotic cells), 78% M2 (apoptotic cells), 22% (our unpublished data).

The resulting determination of the numbers of antireceptor antibody molecules bound/epithelial cell are shown in Table 2. The value for the control antibody represents the autofluorescence of the target cells in terms of the equivalent number of fluorescent-labeled antibody molecules, rather than binding of the control antibody. Thus, a similar value was obtained for target cells with and without control antibody (not shown). 

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