Decanter centrifuge

Resuspend the cell pellet and centrifuge. Decant the supernatant, and resuspend the pellet in 5 mL of fresh fixative. Centrifuge again, and resuspend the pellet in... 

Pellet the cells by centrifugation, decant the supernatant, and add dropwise 5 mL of fixative to the pellet. 

Nuclei already sediment at low accelerations that can be achieved with bench-top centrifuges. Decanting the residue (the supernatant ) and carefully suspending the sediment (or pellet ) in an isotonic medium yields a fraction that is enriched with nuclei. However, this fraction may still contain other cellular components as contaminants—e.g., fragments of the cytoskeleton. 

Two procedures are given for the treatment of the solution in Section A. In the first the solution is cooled down to — 60 °C, and 20 mL of hexane is added. Careful evaporation under vacuum to 20 mL removes most of the CH2 Cl2. The lilac precipitate is isolated by centrifugation ( 2 min at 1500 rpm) and decanting off the solution. Hexane (20 mL) is added at — 60 °C and the suspension is stirred for 10 min. Centrifugation, decanting, and washing are repeated three times. Then the product is dried at — 20 °C for 8 h on a high-vacuum line (10-3 torr). 

If the phases separate themselves by centrifugal decantation state ... 

If the protein precipitates during centrifugation, decant the upper (organic) layer, blend the suspension in the bottom layer again, and then follow the rest of the protocol. 

The next step in the process is removal of remaining soluble and insoluble protein. Starch slurry discharging from the primary centrifugal separator must be diluted with process water to a slurry density of 10-12° Baume (18-21% dry solids). The starch may then be further purified in a second centrifugal separator to a final insoluble protein level of <0.38% dry basis (preferably 0.27-0.32% dry basis). However, since solubles content of the slurry must next be reduced by filtration of centrifugal decantation, the second step currently preferred is to utilize 8 to 14 stages of liquid cyclones which simultaneously remove residual gluten and wash the starch.207-209... 

The A-starch slurry from the centrifugal decanter is screened and then refined either with hydrocyclones or with separators and decanters. Purification and concentration of A-starch is accomplished in multistage hydrocyclones, or the A-starch slurry is separated into A and B fractions in a nozzle-type centrifuge and the A-starch fraction is finally refined in a centrifugal decanter. The B-starch stream is passed through vibrating screens and concentrated in a decanter. Pentosans and other solubles are concentrated and either dried or co-fermented with the B-starch for ethanol production. 

Step 12. Pipette 2 mL of standardized yttrium carrier into the solution and stir, Add concentrated NH4OH drop-wise until white Y(OH)3 precipitates and then add 5 mL in excess. Centrifuge, decant into a centrifuge tube, and save the supernate until the results of the analysis for yttrium have been checked. Record the time. 

Step 2. Add 1 ml iron carrier into each of the first 2 tubes and stir. Add fresh ammonium hydroxide drop-wise with stirring until a brown iron hydroxide precipitate forms. Centrifuge and thoroughly transfer both supernatant solutions to clean centrifuge tubes. Add 5 ml of water to each precipitate, stir, and centrifuge. Decant each wash solution into the corresponding supernatant solution. Discard precipitate. 

The cell free samples were mixed with perchloric acid/perchlorate and stored at low temperature for 48 h, at 6000 rpm centrifuged, decanted, stored at -22°C for a week and centrifuged again for deproteination. The separation was performed on an ion exclusion polystyrene/divinylbenzene column at 40 °C with 15 mM sulfuric acid as eluent and detection at 205 nm. For the quantification a standard was applied. A typical chromatogram is shown in Figure 6. Pyruvate, succinate, lactate, formate and acetate were detected in the cultivation medium. 

The content is again stirred and the test-tube is stoppered and incubated at 35°C for 30 min. After cooling, 0.9 ml of chloroform is added, the mixture is centrifuged, decanted and evaporated almost to dryness with a stream of air. After dissolving the residue in 1 ml of xylene, 0.5 pi is taken for the analysis. 

Pour the medium from the cell culture in step 3 of the growth procedure into the large bottles and centrifuge the cell-containing medium at 5000 X g for 10 min. Following centrifugation, decant the supernatant and discard. 

Add 10 mL of petroleum ether (bp 35-60°C) and boil and manipulate with a spatula until the brown mass has changed to a white paste. Wash the paste into small centrifuge tubes with 10-20 mL of fresh petroleum ether, make up the volume of paired tubes to the same point, cool well in ice, and centrifuge. Decant the brown supernatant liquor into the original tared... 

The separation of the crystals from the residual mother liquors is carried out by a centrifugal decanter specially designed to be capable of operating at the given low temperatures. This phase separation process is facilitated by a great difference in density between solid diacetyl and the residual mother liquors. 

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