Special Internet Prices.
Fast & Guaranteed worldwide Delivery!
Secure & FAST Online ordering.
Our Drugstore Is The Most Trusted Online Drug Supplier.
>> CLICK HERE TO ENTER >>>
Related article: glass slide.
2. With the aid of a forceps take the section or very small quantity
of the material to be examined and spread it on the drop of water.
3. Place a clean cover-glass over the material. In placing the
cover-glass do not drop it flat upon the drop of water, but place one
side of it down first and allow it to squeeze the water along under it.
4. Keep the top of the cover-glass dry.
When filamentous algae or molds are to be examined, the material
tends to cling together and must be carefully separated, in the drop
of water, with dissection needles before the cover glass is placed over
the material. In case a coarse ground drug is to be mounted the
coarser particles should be first crushed in the water on the slide
and subsequently teased apart with dissection needles.
Care should always be taken to see that the water or mounting
medium used is not contaminated with foreign substances. This
can best be practiced by examining the mounting medium under the
microscope before the material to be examined is placed in it.
THE TECHNIQUE OF MAKING PERMANENT MOUNTS
i. The Mounting Medium. When a microscopic object is to be
preserved permanently it must be kept from decaying and the fluid
in which it is placed must be kept from evaporating. These condi-
tions can be met by adding an antiseptic (2 per cent, acetic acid, or
formaldehyde) to the water used in mounting and carefully sealing
the cover glass with asphaltum or zinc white. As a rule, a better
way is to use a mounting medium that will not evaporate, e.g.,
glycerine, glycerin gelatin or Canada balsam. These fluids have
a high refractive index and so render the objects penetrated by them
more transparent. This quality is generally an advantage, but for
objects already almost transparent it is quite the reverse. Glycerine
has the disadvantage of always remaining soft, so that the mount
may at any time be Buy Amoxil Online spoiled by careless handling. "Glycerin-gelatin
FUNDAMENTAL CONSIDERATIONS 21
has the advantage of mixing ' readily with 50 per cent, glycerin in
which the object should be placed before being mounted in this
medium. It should be warmed on a water bath before using and the
cover glass applied quickly after it is placed on the specimen. It
cools rapidly and constitutes the quickest and simplest means of
effecting a durable permanent mount. Its disadvantage is due
mainly to its jelly like consistency which is frequently responsible
for Buy Amoxil Online damaged mounts when the cover glass above the preparation is
too greatly strained. Canada balsam, slowly becomes solid, so
that the mount is exposed to no accident short of actual breakage.
Balsam has Buy Amoxil Online the disadvantage of being non-miscible with water, so
that before it can be used the object must be carefully dehydrated.
Even after this is done, and the object lying in absolute alcohol, an
oil must be used as an intermediate agent between alcohol and
2. Staining. For two reasons it is generally better to stain plant
tissues before mounting. Transparent tissues may become almost
invisible in glycerine, glycerin-gelatin, or balsam, and different
tissues take a stain differently. This being the case it becomes
possible to stain one tissue and not another, or one tissue with one Buy Amoxil Online
stain and another in the same section with a different stain, so that
the different parts may be brought out like areas on a colored map.
The most common stains are haematoxylin derived from logwood, and
various anilin stains safranin, fuchsin, eosin, iodine Buy Amoxil Online green, methyl-
green, malachite green, etc.
METHOD FOR THE 'PREPARATION OF A CANADA BALSAM MOUNT
1. Stain object with 0.5 per cent, solution of safranin or fuchsln
in 50 per cent, alcohol for from three to five minutes.
2. Wash out excess of stain and further dehydrate with 70 per
3. Stain with 0.5 per cent, solution of methyl-green, or malachite
green, or iodine-green in 70 per cent, Buy Amoxil Online alcohol for twenty seconds or
longer, depending upon the nature of the material.
4. Dehydrate and wash out excess of stain with 95 per cent, alcohol
for two minutes.
22 PHARMACEUTICAL BOTANY
5. Further dehydrate by placing material in absolute alcohol for
6. Clear in cedar oil for i minute. Blot up excess from around
edge of section.
7. Mount in Canada balsam.
8. Label slide.
Should air-bubbles be detected in the balsam shortly after mount-
ing, heat a dissection needle in a flame and touch each with its tip,
when they will be Buy Amoxil Online found to disappear.
If too much Canada balsam has been used, some of it usually
spreads beyond the edge of the cover-glass, or on its surface. In
this event wait until the balsam hardens, when it can Buy Amoxil Online be scratched
off with a knife, and the surface of the glass cleaned with a rag
moistened with turpentine oil or xylol.
Should the Canada balsam become too thick, it can be thinned
down with either xylol or benzol.
METHOD FOR THE PREPARATION OF A GLYCERIN-GELATIN MOUNT
1. Stain object with an aqueous solution of eosin.
2. Wash out excess of stain by moving the section about in a
dish of water.
3. Transfer object to weak glycerin (glycerin 10 parts, water
90 parts) for 3 to 5 minutes.
4. Transfer object to 50 per cent, glycerin for 3 to 5 minutes.
5. Transfer object to concentrated glycerin for 5 Buy Amoxil Online minutes.
Related post: Clomid Without Prescriptions Uk, Order Naprosyn, Purchase Flagyl, Buy Cheap Flagyl, Buy Zithromax Online, Zithromax Buying, Buy Zelnorm Online, Purchase Neurontin, Neurontin Tablets Scored, Effexor Cheap