S1 L4 Microscopy Cell Inclusions

7/29/2019 S1 L4 Microscopy Cell Inclusions

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S1 L4 Evaluation of plant drugs

1. Botanical

B. Microscopy

Cell inclusions

Anna Drew


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Cell inclusions

Parenchyma cells Contain characteristic contents of living protoplasts

Eg nucleus, cytoplasm, vacuoles, plastids,

mitochondria

Not diagnostically useful

Non-protoplasmic components Classified as ergastic substances

Starch

Protein

Oil

Crystals

Very useful for identification


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1. CALCIUM OXALATE

Crystals may be reserve or waste products ofcellular activity

Oxalate ions removed in making crystals

Dont know why they arise (could be pH)

Or why they are found in particular locations

(vascular tissue) and not others (near veins)

Clearing agents: Chloral hydrate solution to remove chlorophyll (cell walls

etc remain)

Show in crossed polaroids

Comment on size, shape, frequency


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(a) Prisms

One prism per parenchyma cell

Cells form a sheath around fibres in vascular bundle

Eg cascara, senna, liquorice

Hyoscyamus leaf

Twin crystals


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Calcium oxalate of

Cassia acutifolia

(senna) leaflet

(viewed under high

power)

Note cluster

crystals also present

in senna leaflet


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(b) Clusters & rosettes

Microrosettes in Umbelliferae eg anise, fennel

Eg Senna

Cascara

Stramonium

Eg Rhubarb

rhizome


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Calcium oxalate

ofDatura

Stramonium leaf(viewed under

high power)

Calcium oxalate

ofDatura

stramonium leaf

(viewed underlow power)


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(c) Needles (acicular)

Occupy the whole parenchyma cell

Next cell contains none

Eg ipecacuahna, squill

Calcium oxalate ofCephaelis

ipecacuanha rhizome

(viewed under high power)


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(d) Microsphenoids (crystal sand)

Very small

Adjacent cells dont store them

Eg belladonna

Calcium oxalate ofAtropa belladonna

leaf (viewed under high power)


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2. CALCIUM CARBONATE

Not as common as calcium oxalate Eg cannabis cell

Calcium carbonate

deposit


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3. STARCH GRAINS

More common

Occur as discrete grains

Commonly show layering of amylose & amylopectin

around a point hilum

Found in parenchyma of pith, cortex, vascular tissues,

fruits, cotyledons & seed endosperms

Generally not found in leaves transported out

Staining:

Dilute glycerin

Chloral hydrate to dissolve pigments

* I2 blue-black stain

* Polarised light not bright

Maltese cross

effect (page 15

microscopy

notes)

* Characteristics

of plant starch


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Shape

One shape will be dominant or characteristic of a

plant Eg Polyhedral maize starch

Ovoid with a few round potato

Sac shape ginger

Aggregation

Can be single, 2, 3 -> multicompound grain

Eg ipecacuanha

Size Rice 6 m

Potato 45-70 m


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Hilum

Striations Present or absent

Layers of amylose and amylopectin

Frequency Absent rare abundant (90% of plant material)

Location Where they are found Eg root, rhizomes, seeds etc

May just be in specific tissues Eg pith, cortex, perisperm

Single

point

Line in a

grain Cleft Stellate

Punctate

(hole)


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Potato starch grains


Maize starch grains


Cephaelis ipecacuanha

rhizome starch


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4. PROTEIN

Indicative of seed material

Diagnostic feature: Picric acid stains protein yellow

Allow a few minutes to stain, wash away rest

Amorphous

Crystalloid protein

Amorphous protein

Globoid

Calcium

oxalate

Phosphorus

protein

Aleurone Eg Linseed


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5. OILS, FATS

May float out in stain to below coverslip

Fixed oil Esters of glycerol

Eg linseed, olive

Volatile (essential) oil

Look the same

Turpine and hydrocarbons

Eg peppermint

Can smell

Staining:

Sudan III, Tincture of Alkanne

Some plants contain so much oil that it needs to be removed

to see other structures

Light petroleum removes fat

Mix, decant off, repeat several times, then can stain

Globules


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6. MUCILAGE

Sometimes present

Has to be stained to be seen

Staining:

Ruthenium red -> pink

Eg senna leaves

S1 L4 Microscopy Cell Inclusions

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