MICROSCOPIC IMAGES

of VARIOUS CELL

SAMPLES

Various experiments have been conducted in the Cell Biology and Genetics Laboratory in VIT , Vellore, under the guidance and instructions of Prof. Gayathri M.

The experiments mostly include

simple staining of various type of cell samples using simple tools , observance under light microscope and noting down their characteristics.

Here I have put forward the microscopic images and observations in brief, which I have taken and collected, of the sample cells corresponding to the several experiments conducted in the lab till date (Six Experiments).

Blood Grouping was the first experiment that was conducted. Individual blood was used as sample. My blood type was confirmed as B+. Anti serums were the reagents/ chemicals used to observed agglutination which occurred in Antiserum B and Antiserum D but not in Antiserum A (as seen in pic.).

FACTS: i. 35 blood group systems have been identified. The most familiar is the ABO

system including the Rh systems, and an individual’s blood type is one of the many possible combinations of blood group antigens.

ii. Across the 35 blood groups, over 600 different blood group antigens have been discovered.

iii. Almost always, an individual has the same blood group for life, but very rarely an individual’s blood type changes through addition or suppression of an antigen in infection, malignancy or autoimmune disease and bone marrow transplant.

iv. Type O blood must consume a high-protein diet heavy on lean meat , poultry, fish vegetable, and light on grains, beans and dairy.

v. A meat free diet rich in fruits and vegetables, beans and legumes, and whole grains-ideally, organic and fresh should be consume for Type A blood.

vi. Type B blood group should focus on green vegetables, eggs, certain meats and low fat dairy. Corn, wheat, lentils, tomatoes, peanuts and sesame seeds must be avoided.

vii. The foetus inside a pregnant woman may have different blood group from the mother.

Second experiment was Blood Smearing with Leishmanns’ stain.Blood sample was collected. The presence of platelets structures , granulocytes (neutrophils, eosinophils and basophils) and agranulocytes (lymphocytes and monocytes) in the blood sample was observed.

FACTS:i. The kidney regulates red blood cell production by releasing the hormone

erythropoietin (EPO) which travels to the bone marrow, when the blood oxygen level is low.

ii. Cytoplasm of erythrocytes are rich in haemoglobin, an iron containing biomolecule that can bind to the oxygen and is responsible for the red colour of the cells

iii. The only vertebrate without erythrocytes are the crocodile icefishes (family Channichthyidae). They live in very oxygen-rich cold water and transport oxygen freely dissolved in the blood. While they do not use haemogoblobin anymore, remnants of haemoglobin genes can be found in the genome.

iv. Erythrocytes in mammals are anucleate when mature as well as salamanders of Batrachoseps genus and the fish of the Maurolicus genus. The other vertebrates, on the other hand are nucleated.

v. The elimination of nucleus offers the explanation for subsequent accumulation of non-coding DNA in the genome.

vi. The human embryonic stem cells could be coax into becoming an artificial erythrocytes. The cells can be induce to inject their nucleus by growing the cells on stromal cells from the bone marrow. This was done for the first time in 2008 and are hoped to be eventually used for blood transfusions.

The third experiment was to observe Osmosis in Onion Cells.Here two different conc. of external solutions (i.e., hypotonic and hypertonic) is taken, in which the cell was immersed for a while.The cells show bulkiness and shrinkage respectively in the two types of concentrations.

FACTS:i. The epidermal cells of onions provide a protective layer

against viruses and fungi that may harm the sensitive tissues.

ii. Onion epidermis is unilayer and does not contain any chloroplast, because the onion fruiting body (bulb) is used in storing energy, not photosynthesis.

iii. Vacuole is prominent and present at the centre.iv. Due to its simple structure and transparency, they are

used in introducing plant anatomy and plasmolysis.

Observance of Meiosis in Plant Flower Bud was the fourth experiment. Acetocarmine was used for staining.Several stages of meiosis was observed. The image here represents Telophase (either I or II) where splitting of chromosomes have already occurred.

FACTS:i. Meiosis occurs in eukaryotes, however, some mammals do not have the

ability of meiosis and have acquired the ability to reproduce by parthenogenesis.

ii. First discovered in sea urchin eggs.iii. Cycling meiosis produces a series of transitions back and forth between

alternating diploid and haploid state.

The fifth experiment was to confirm the presence and absence of Barr Bodies in the cells of female and male respectively.Buccal epithelial cells of each individuals was the sample, which was stained with acetocarmine. When viewed under the microscope, there was lack of barr bodies in the cells as predicted for male , however it was present in female cells.

FACTS:i. A Barr body is the inactive X chromosome in a female somatic cell, in those

species in which the sex is determined by the presenceof the Y or W rather than the diploidy of the X.

ii. In cells with multiple X chromosomes all but one are inactivated during mammalian embryogenesis which happens early in embryonic development at random in mammals. This is known as Lyon hypothesis.

iii. Lyon hypothesis doe s not correlate in species such as marsupials and in some extra embryonic tissues of some placental mammals, in which the fathers’s X chromosome is always deactivated.

iv. In humans with more than one chromosome, the number of Barr bodies visible at interphase is always fewer than the total number of X chromosomes.

v. Men with Klinefelters syndrome have a single Barr bodies, women have one and male have none.

vi. Barr bodies can be seen on the nucleus of neutrophil.

Mitosis in Onion Root Tip was the corresponding sixth experiment.The cells were stained in acetocarmine and observed under the light microscope.Several stages of the mitotic cell divisions could be seen as well as splitting of few cells as seen in the figure.

FACTS:i. Mitotic errors can create aneuploid cells that have too few or

manyy of one or more chromosomes.ii. Anaphase lag occurs when the movement of one chromatid is

impeded during anaphase due to inability to attach the chromosome to the spindle.

iii. Endoreduplication occurs when chromosomes duplicate but the cells do not divide which results in polyploidy or, if the chromosomes divide repeatedly, polytene chromosomes.

iv. Endomitosis is a variant of endoreplication in which the cells replicate their chromosomes during S phase and enter, but prematurely terminate, mitosis. Instead of dividing into two daughter nuclei, the replicated chromosomes are retained within the original nucleus.

I would like to acknowledge our Cell Biology and Genetics faculty Prof. Gayathri M. and also the RAs for their guidance on the subject as well as making it a fun and enjoyable learning process.

Images taken are of low quality due to low megapixels of the phone with which they were taken.

More slides would be uploaded in the future as experiments continue further in the lab. So keep following!

THANK YOU !