Accession Number:

AD0602496

Title:

PRESERVATION OF BIOLOGICAL MATERIALS BY FREEZEDRYING

Descriptive Note:

Final rept. for 1 Jul 62-31 Mar 64

Corporate Author:

MALECKI LABS INC CHICAGO IL

Personal Author(s):

Report Date:

1964-03-31

Pagination or Media Count:

35.0

Abstract:

The feasibility of freeze-dehydrating biological materials by extracting frozen moisture with dry cryogenic liquids in the presence of dessicants was investigated. Freeze-dehydration of hydrated gelatin capsules in liquid nitrogen and liquid nitrous oxide proceeded too slowly to be evaluated. Dehydration was feasible in ethyl ether and ethyl alcohol at dry ice-alcohol temperature -78.5C. The presence of a dessicant in the de hydration system was found to be essential for complete drying. A sequential vacuum freeze drying-nitrous oxide critical point dehydration technique was used to obtain porous dehydrated meat tissue. Dehydration of partially freeze dried meat tissue 10 residual moisture was also carried to completion 1 moisture in a dry liquid at -78.5Cin the presence of molecular sieves. Preliminary data indicated that microorganisms can be similarly dehydrated with retention of viability. Author

Subject Categories:

  • Biochemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE