Section cutting techniques: BP112RBP Remedial Biology Practical

Aim:

To understand the different section cutting techniques for different parts of a plant.

Theory:

Different sections can be obtained from a stem, root or stolon depending on the plane of cutting, each section revealing details from different angles.

Transverse section (TS):

The transverse section is obtained by cutting along the radial plane of a cylindrical portion of the stem, root, stolon and perpendicular to the long axis.

This section when prepared and observed under a microscope reveals the radial arrangement of tissues and shows concentric layers and vascular bundles.

In order to reveal the tissue arrangement longitudinally viz along the parallel planes to the long axis both radially and tangentially, we have to cut the longitudinal sections.

Longitudinal Section (LS):

Tangential longitudinal section (TLS): A section cut along the long axis parallel to the tangent

Radial Longitudinal section (RLS): A section cut along the long axis and the cutting plane passing through the long axis and radius.

Significance of TS, TLS and RLS:

Observation of section of a stem/ root/ stolon in TS, TLS and RLS reveals the structure and morphology of a particular cell from all angles. At the same time arrangement of cells in a tissue is revealed from all angles.

Section of a leaf:

Unlike in stem, root, stolon in the case of leaf the important aspect is to study the section through the midrib taken perpendicular to the midrib and observation of the surface preparation.

In the case of a bilateral leaf, either surface may be observed but in the case of a dorsiventral leaf, the lower epidermis is more important, bearing the stomata, guard cells and epidermal cells. Surface preparation is many times used as an identification tool by means of morphology and leaf constants.

Section of a bark:

In the case of a bark transverse section is important as it reveals the horizontal arrangement of cells and shows lenticels. RLS helps to reveal the arrangement and thickness of the cells.+

Section of fruit and seed:

In the case of fruit and seeds generally, TS of various parts are observed under the microscope: e.g. In the case of Umbelliferous fruits like fennel, The TS of mericarp is observed while in the case of cardamom TS of pericarp and seed is studied. Thus in the case of fruits and seed drugs, a separate sectioning technique is required for the individual drug. Sometimes longitudinal sections cut through the centre of the seed of the fruit have been useful in an investigation.

Preparation of sample for sectioning:

Put the sample selected in a test tube and add sufficient chloral hydrate solution or water so that the same remains submerged. Boil the sample in water over a bunsen burner/ flame for a few minutes. This will soften the hard drug sample and will help in obtaining fine sections. In the case of a leaf, this step may not be necessary.

For a stem/root/stolon drug, cut a cylindrical portion of which is almost straight and cut off both edges so as to make the edges smooth. This sample is ready for section cutting. Hold the sample vertical between the first, second finger and the thumb and move the blade back and forth from one end to the other, obtaining the slices. Take a sufficient number of sections, as all sections will not be very fine and uniform.

Transfer the section to a watch glass containing water with the help of a brush. Reject thick and oblique one.

Similarly, cut sections of the leaf in the block of pith which shall give sections of the leaf when separated from the pith. Transfer the sections to a watch glass with a brush.

Note: Before taking the section, ensure that the blade is having enough amount of water on its edge if a dry blade is used, it shall entrap air bubbles in the section, which are difficult to remove. In the case of leaf drug, cut a part of the leaf passing through the midrib. This cut off portion may or may not be boiled (boil it only if it is a drug and requires boiling with water for softening) since the lamina of a leaf is very thin, section cutting is difficult. The surface area of the surface to be cut has to be increased. This is done by embedding the sample in a block of pith. This pith is obtained from red pumpkin or raw papaya or potato. A cubical portion of the pith is cut off and used.

Remedial Biology Practicals

Introduction to experiments in biology a) Study of Microscope b) Section cutting techniques c) Mounting and staining d) Permanent slide preparation 2. Study of cell and its inclusions 3. Study of Stem, Root, Leaf, seed, fruit, flower and their modifications 4. Detailed study of frog by using computer models 5. Microscopic study and identification of tissues pertinent to Stem, Root Leaf, seed, fruit and flower 6. Identification of bones 7. Determination of blood group 8. Determination of blood pressure 9. Determination of tidal volume

First Year B Pharm Notes, Syllabus, Books, PDF Subjectwise/Topicwise

First Year B Pharm Notes, Syllabus, Books, PDF Subjectwise/Topicwise

F Y B Pharm Sem-I	S Y B Pharm Sem-II
BP101T Human Anatomy and Physiology I Theory	BP201T Human Anatomy and Physiology II – Theory
BP102T Pharmaceutical Analysis I Theory	BP202T Pharmaceutical Organic Chemistry I Theory
BP103T Pharmaceutics I Theory	BP203T Biochemistry – Theory
BP104T Pharmaceutical Inorganic Chemistry Theory	BP204T Pathophysiology – Theory
BP105T Communication skills Theory	BP205T Computer Applications in Pharmacy Theory
BP106RBT Remedial Biology	BP206T Environmental sciences – Theory
BP106RMT Remedial Mathematics Theory	BP207P Human Anatomy and Physiology II Practical
BP107P Human Anatomy and Physiology Practical	BP208P Pharmaceutical Organic Chemistry I Practical
BP108P Pharmaceutical Analysis I Practical	BP209P Biochemistry Practical
BP109P Pharmaceutics I Practical	BP210P Computer Applications in Pharmacy Practical
BP110P Pharmaceutical Inorganic Chemistry Practical
BP111P Communication skills Practical
BP112RBP Remedial Biology Practical

Section cutting techniques: BP112RBP Remedial Biology Practical