Biology Reference
In-Depth Information
FIGURE 21.4
Specimen table loading device. The specimen table (1) with its lever in the loading position
(2) is inserted into the specimen table loading device (3) and submerged in a Dewar filled
with liquid nitrogen. Mica sandwiches are then deposited onto the supporting table (4), split
with fine-tipped tweezers, and the sample containing mica sheet is loaded into the
specimen table, using the cut corner as a reference for the correct orientation. Note that for
clarity sake, the image has been taken in absence of liquid nitrogen, which under
operating conditions should cover all the objects within the Dewar.
FIGURE 21.5
Floating and washing of replicas. The mica is held with a pair of fine tweezers with the replica
side facing upward and submerged gently at a 30
-45
angle into domestic bleach solution. The
replica should float on the surface. After overnight incubation, pieces of the replica are picked
upwithamoltenglass pipette (middle panel) and transferred towells filledwith triple-distilledwater.
If upon overnight incubation the replica still consists of one big piece (right panel, lower left well), it is
better to break it into smaller pieces by tapping it gently with the glass pipette. Picking up the
big piece at once would result in folding over itself, making it impossible to analyze afterward.
