Martin-christ Beta 2-8 LDplus User Manual download pdf (Page 9)

Operating Manual Freeze Dryer BETA 1-8 LDplus / BETA 2-8 LDplus General Information  9

1. General Information

1.1. Introduction

What is freeze-drying (Lyophilisation)?

Freeze-drying means: Extraction of water from frozen material.

The drying process takes place by avoiding the liquid state through

sublimation, i. e. direct conversion from ice to vapour. This

happens under vacuum and the temperature in the product is

normally less than -10°C.

The aim of freeze-drying is to obtain an easily water soluble

product which will have the same characteristics as the original

product after addition of water.

As the drying process takes place in frozen state at very low

temperatures it is possible to dry e. g. proteins which will not

denature. Also most of the other chemical compounds will be

qualitatively and quantitatively unchanged.

Through freeze-drying the product, mainly of biological origin -

such as tissues, tissue extracts, bacteria, vaccines and sera - is

transformed into a dry product. During this process enzymatic,

bacterial and chemical changes are largely avoided.

Freeze-drying (lyophilisation) is the most gentle process for

preserving the biological properties of sensitive tissue and tissue

components.

Lyophilisation is also the best method when drying inorganic

products – e.g. nanoscale dispersions – the particle surfaces of

which should remain unchanged.

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Martin-christ Beta 2-8 LDplus User Manual Page 9