Cryopreservation allows for storage of biological materials at ultra
low temperatures, while minimizing the level of freezing damage
to cells. An important factor to consider when preserving cells
or tissue at cryogenic temperatures is to prevent amorphous ice
crystals from recrystallizing within and outside the cells. These
ice crystals increase the degree of freezing damage to cells.
-130°C is the recrystallization point of pure water in the ultra-low
temperature zone. This is the temperature at which amorphous
ice crystals recrystallize. For a mixed solution containing Me2SO
and other cryoprotectants, recent research confirms that
recrystallization occurs around -115ºC. Thus samples maintained
in an ultra-low temperature freezer at -150ºC, far lower than the
recrystallization point, can be semi permanently preserved. Such
preservation maintains vitrification without further crystallization
within and outside cells. Other recent findings show that
preserving cattle sperm at -135°C is insufficient, and also that
superconductivity experiments
require temperatures of at least
-148ºC. These cases show the
increased necessity of -150ºC
freezing in a diverse array of
cryogenic applications.
VIP
®
Plus
™
Design
• SANYO V.I.P.
®
PLUS™ Cryogenic Series -150°C ultra-low
temperature freezers use patented revolutionary vacuum
insulation cabinet construction that reduces the wall thickness
from 175mm to 135mm (6.9” to 5.3”) and achieves up to 25%
more storage capacity than a conventionally insulated freezer
without increasing the footprint.
• This design prevents the insulation layers from distortion and
cracking that might occur due to temperature differences inside
and out, and creates the most efficient insulation material
available today.
• Moisture condensation at the top edges of the cabinet due
to differences in temperature inside and out causes frost and
icing problems, which may reduce heat insulation efficiency
and obstruct door movements. These
obstructions are prevented by the
“hot line” which prevents frost and
condensation from forming on the gasket
and mullion
• The newly developed refrigeration
system and the freezer structure offer a
quiet experimental environment.
• Achieves 50% higher energy
conservation than conventionally
insulated model.
Specially Designed Compressor for
Cryogenic Temperatures
The refrigeration system is at the heart of producing cryogenic
temperature freezing. In the process of developing various
technical solutions in order to achieve and maintain cryogenic
temperatures, SANYO designed the compressor specifically
for this use. SANYO is a leading manufacturer of cryogenic
temperature freezers.
Liquid Nitrogen Vapor Storage
Mechanically Refrigerated Cryogenic Freezer
–80°C
–130°C
–152°C
Recrystallization point
Hexagonal crystal
Cubic crystal
Amorphous
ice crystal
Why Freeze to –152°C?
Recrystallization Mechanism (Artist’s Concept)
–86
°C
–86
°C
–152
°C
–152
°C
Alarm lamp and buzzer
Filter check lamp
Buzzer key
Alarm test key
Mode setting key
Digit shift key
Numerical value shift key
Enter key
Power switch
CO
2
Back-up test swich (AT type only)
CO
2
Back-up swich (AT type only)
Battery switch
Remote alarm switch
Temperature recorder
Control panel
Hot line
MDF-393AT
1
2
3 4 5 6 7 8
9
10
12
13
14
11
1
2
3
4
5
6
7
8
9
10
12
13
14
11
Optional Accessories
Model No.
Recording Range
Freezer Model
MTR-85H
–100 to +50°C
MDF-192
MDF-393
MDF-593
MDF-793
MTR-155H
–170 to +30°C
MDF-1155
ULT-Freezer Backup Kits
CVK-UB2/UB2(
I
):
LCO
2
Backup Kit for MDF-793/593/393
CVK-UBN2/UBN2(
I
):
LN
2
Backup Kit for MDF-793/593/393
CVK-A:
Built-in LCO
2
Backup Kit for MDF-793/593/393/192
CVK-AT2:
LCO
2
Backup Kit for MDF-1155
CVK-ATN2:
LN
2
Backup Kit for MDF-1155
Temperature Recorders
(
I
) version for North America only
–80°C
–130°C
–152°C
Recrystallization point
Hexagonal crystal
Cubic crystal
Amorphous
ice crystal
Why Freeze to –152°C?
Recrystallization Mechanism (Artist’s Concept)
–86
°C
–86
°C
–152
°C
–152
°C
Alarm lamp and buzzer
Filter check lamp
Buzzer key
Alarm test key
Mode setting key
Digit shift key
Numerical value shift key
Enter key
Power switch
CO
2
Back-up test swich (AT type only)
CO
2
Back-up swich (AT type only)
Battery switch
Remote alarm switch
Temperature recorder
Control panel
Hot line
MDF-393AT
1
2
3 4 5 6 7 8
9
10
12
13
14
11
1
2
3
4
5
6
7
8
9
10
12
13
14
11
Optional Accessories
Model No.
Recording Range
Freezer Model
MTR-85H
–100 to +50°C
MDF-192
MDF-393
MDF-593
MDF-793
MTR-155H
–170 to +30°C
MDF-1155
ULT-Freezer Backup Kits
CVK-UB2/UB2(
I
):
LCO
2
Backup Kit for MDF-793/593/393
CVK-UBN2/UBN2(
I
):
LN
2
Backup Kit for MDF-793/593/393
CVK-A:
Built-in LCO
2
Backup Kit for MDF-793/593/393/192
CVK-AT2:
LCO
2
Backup Kit for MDF-1155
CVK-ATN2:
LN
2
Backup Kit for MDF-1155
Temperature Recorders
(
I
) version for North America only
-150
°
C Cryogenic Temperature Freezer
Comparison of temperature distribution in a liquid nitrogen freezer (vapor phase) and SANYO’s MDF-C2156VANC
mechanically refrigerated cryogenic freezer. Graph shows temperatures at different locations within the chamber. This data
demonstrates that 100% of the MDF-C2156VANC storage space maintains uniform storage temperatures safely below
-130ºC, while temperature in LN
2
vapor system is dependent on storage location.
