4. Chaetoceros neogracilis can be successfully cryopreserved using
a passive freezer (see Note 6) with the tubes placed in the rack
that fits in the bath of isopropyl alcohol. The passive freezer is
placed in the À80
C freezer for 100 min, and the isopropyl
Table 2
(a) Cryopreservation of diatom genera at the RCC using the standard protocol detailed in Note 1.
(b) Cryopreservation of diatom classes/orders at the RCC using the standard protocol detailed in Note
1. (c) Success rate of diatom cryopreservation at the RCC according to geographic origin. (d) Success
rate of diatom cryopreservation at the RCC according to cell volume
(a)
Genus
Successful
Not successful
Thalassiosira
36
25
Minidiscus
32
28
Nitzschia
31
0
Skeletonema
22
3
Chaetoceros
16
8
Minutocellus
7
0
Cylindrotheca
5
0
Guinardia
0
6
Other/unknown
35
24
184
94
(b)
Class
Order
Successful
Not successful
Mediophyceae
Thalassiosirales
89
56
Chaetocerotales
17
8
Cymatosirales
19
6
Bacillariophyceae
Bacillariales
38
0
Coscinodiscophyceae
Rhizosoleniales
0
6
(c)
Origin
Successful
Not successful
% Successful
Temperate
137
77
64%
Polar
30
16
65%
Tropical
17
1
94%
(d)
Category
Cell volume
Successful
Not successful
% Successful
Small
<1000 μm
3
115
51
69%
Medium
1000–2500 μm
3
67
31
66%
Large
>2500 μm
3
2
12
14%
Cryopreservation of Algae
613