To prepare stained temporary mount of onion peel Video Lecture - Class 9

to prepare stained temporary mount of
onion peel
materials required medium sized onion
slide cover slip watch glass forceps
knife needle distilled water glycerine
dropper blotting paper safranin solution
compound microscope brush
procedure take a medium sized onion and
cut it literally into four to five
pieces with the help of a knife
remove a scale leaf from one of the
pieces break the scale leaf gently from
the middle and peel a small portion from
the delicate epidermis that is the
covering that covers the inner surface
of the scale leaf
remove the delicate epidermal peel with
the help of forceps and place it in a
watch glass containing distilled water
take another watch glass and place in it
three to four drops of safranin solution
with the help of brush transfer the peel
in water into the safranin solution for
staining wait for two to three minutes
transfer the peel back to the watch
glass containing water this will remove
the extra stain sticking to the peel
take a clean glass slide and pour 1 to 2
drops of glycerine
transfer the stained bill on the drops
of glycerine on the slide with the help
of brush the peel may tend to curl up
with the help of needle and brush
flatten the peel place the cover slip on
the slide in such a way that no air
bubbles enter in it gently press the
cover slip with needle to spread
glycerine and peel properly remove the
extra material surrounding the slide
with the help of blotting paper examine
the slide under compound microscope
observation there a large number of
cells lying side by side with distinct
cell walls a largely stained nucleus is
present in the periphery of cytoplasm a
lightly stained cytoplasm is the
periphery of cell wall a prominent
vacuole is the center of each cell
surrounding by cytoplasm inference the
cells under observation are the plant
cell it because cell wall and large
vacuums are clearly seen