Wash grid

Lead citrate/uranyl acetate6 Step 1 Float or immerse sections for 10-30 min on filtered 1-2% aqueous uranyl acetate (or in EtOH) wash with ultrapure H20 (three beakers of 50 mL each) by dipping grids held with a forceps dry for 5 min Step 2 Place drops of lead citrate (lead carbonate free) onto a wax surface (parafilm or dental wax) in a Petri dish line edges of dish with pellets of KOH float grid with sections (sections face down) for 4-5 min (if overstained 2-3 min and dilute stain) wash grids with sections in ultrapure H20 Nonselective enhancement of membrane contrast, ribosomes, and nuclear material proteins and lipid droplets... 

Wash grids with 15 drops of phosphate buffer, pH 6.5, drain and transfer to 15-p.L drops of sap extract containing virus, diluted in phosphate buffer, pH 6.5, to 1 500. Incubate at room temperature for 30 min. 

Wash grids by holding in the forceps and dropping 30 drops of phosphate buffer in a constant stream using a Pasteur pipet on the treated side. Drain excess liquid with filter paper and place on PAG for 15 min at room temperature. 

Select a suitable size of PAG (see Note 20) to 1 50 in phosphate buffer pH 6.5 on the Parafilm. Wash grids as before and place them on the PAG and incubate at room temperature for 15 min. 

Wash grids as before and place them on the antiserum for 15 min. 

Wash grids as before. Drain excess liquid with filter paper and place on the PAG for 15 min. 

Dilute a larger size of PAG particle, for example, 20 nm, wash grids as before, and place them on the PAG and incubate for 15 min as before. 

After adhesion, wash grid on three successive drops of 50 mAf NaCl (see above). 

Figure 3.15 Specifications of the second absorber (HVCO and wash grid zone).

The bottom section of the main column provides a heat transfer zone. Shed decks, disk/doughnut trays, and grid packing are among some of the contacting devices used to promote vapor/liquid contact. The overhead reactor vapor is desuperheated and cooled by a pumparound stream. The cooled pumparound also serves as a scrubbing medium to wash down catalyst fines entrained in the vapors. Pool quench can be used to maintain the fractionator bottoms temperature below coking temperature, usually at about 700°F (370°C). 

Collect sections on acetone-washed copper grids (see Subheading 2.2.) View directly or positive stain with uranyl acetate and lead citrate (sections can be stored in a grid box)... 

The grids are then washed with buffer as before to remove the excess gold particles. The grids should then be dipped in distilled water for a few seconds to remove excess buffer before staining. Uranium stains can form precipitates with a variety of substances and the removal of the buffer helps ensure a good staining of the section. 

Place the microtubes with grids at room temperature and allow them to cool for about 15 20 min. Before the beginning of the immunogold labeling protocol (see below), grids should be washed by dipping them repeatedly in water for 45 60 s. 

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