Freeze stages

Lyoprotectants can affect enzyme stability in both stages of lyophilization the freezing and the drying stages. In the freezing stage of lyophilization, ice crystals form and have been shown to be a cause of enzyme denaturation. Studies have shown that when added as a lyoprotectant, the amorphous polyol mannitol stabi-... 

For optical microscopy, hairy root specimens were fixed with 3 % formaldehyde in 50 mol m phosphate buffer (pH 6.8) for 1 h at ambient temperature. Cross-sections of the specimen were prepared using a sliding microtome equipped with a specimen-freezing stage. The sections were examined with microscopes under conventional or fluorescent light (excitation wavelengths of 520-550 nm and emission wavelength of >580 nm). 

Raman Spectroscopy Measurements. The methane molecules in hydrate were analyzed by Raman spectroscopy by use of a laser Raman microprobe spectrometer (JASCO NSR-1000). The temperature of hydrate crystal was kept constant at 253 K during Raman measurements and heating the sample F by use of a freezing stage (Linkam LK-FDCSI). 

Oxford Instruments, Inc. Heating and freezing stages for electron microscopes Concord, Massachusetts, U.S.A. Tel 1-508-369-9933... 

After the spray-freezing stage is finished, suitable drying conditions are selected, i.e., the liquid nitrogen cooler is adjusted to meet freeze-drying conditions for the product. The drying time and actual operation conditions need to be determined by testing in the laboratory. 

In the freezing stage, the foodstuff or solution to be processed is cooled down to a temperature at which all the material is in a frozen state. 

The solidification or freezing stage, during which crystal growth takes place at the constant equilibrium freezing temperature, Tf, until the droplet is completely solidified. 

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