Sequential Replicas for In Vivo Imaging of Growing Organ Surfaces - Plant Cell Morphogenesis: Methods and Protocols - page 99

4. Any type of dental silicon polymer.
5. Wooden toothpicks and fi ne forceps.

2.3 Mold Preparation

1. Dental silicon (polyvinyl) impression material dedicated for
obtaining patient's mouth impression of the fi nest details,
with work time circa 2 min and total set time 5 min. It is better
to use less hydrophilic materials ( see Note 3 ). We recommend
Take 1 (the hydrophilic vinyl; wash material; regular set) man-
ufactured by Kerr Corporation. Original product is available as
a pair of cartridges with two differently colored pastes. You
will need only small equal-volume amounts of the pastes each
time. Thus, it is convenient to put a small amount of the two
pastes in two disposable syringes (5-10 ml volume) and close
syringes by original caps or short injection needles.
2. Silicon sealant (clear, used for plumbing).
3. Wooden toothpicks, dental fi lling instruments or excavators,
fi ne forceps, glass slides, and disposable petri dishes.

1. Epoxy resin (transparent with long setting time, preferably
setting overnight). We use Devcon 2 t epoxy, transparent and
long setting.
2. Epoxy gel ( see Subheading 2.2 , item 3 ).
3. Scanning electron microscopy (SEM) stubs.
4. Wooden toothpicks, fi ne forceps, razor blades, injection
needles, thin glass tubes with ends stretched and thinned in a
fl ame, dental fi lling instruments or excavators, and disposable
petri dishes.

2.4 Cast Preparation
and Observation by
Scanning Electron
Microscopy

In case of items 1 and 2 put some of the two resin components
in two disposable syringes (10-15 ml volume), and close them by
original caps or short injection needles (only a small amount of a
resin is used each time).

3 Methods

Carry out all procedures at room temperature, not below 16 °C
and not exceeding 24 °C ( see Note 4 ). High air humidity is prefer-
able. The spectrum of light and its intensity during the mold tak-
ing (steps described in Subheadings 3.1 and 3.2 .) are limited
mainly by the type of organ and process under investigation that
may require usage of stereomicroscope, monochromatic light, etc.

3.1 Exposing the
Examined Organ
Surface

The surface of interest has to be at least partly and temporally
exposed so that the dental silicon polymer, which is fl uid during
application, may fl ow onto the surface ( see Note 5 ). The described