Polytene Chromosome: Video explains the complete laboratory procedure of temporary slide preparation of Polytene Chromosomes (giant chromosome) in Drosophila Salivary Glands with dissection. This practical comes under Genetics lab exercises.
Preparation of Polytene Chromosomes in Drosophila Salivary Glands :
For detailed information visit: www.ebiologylab.com/experimen...
Materials required: Preparing a wet mount slide.
i) 4th instar Drosophila larvae
ii) Two pointed needles
iii) Microscope slide and coverslip
iv) Dissecting microscope
v) Aceto-alcohol (1:1) fixative
vi) Aceto-orcein stain
vii) 45% acetic acid
viii) Compound microscope
ix) Large watch glass or petri dish
x) Blotting papers
********************************************************************
The procedure of preparation of Polytene Chromosomes in Drosophila Salivary Glands:
A) Dissection of Drosophila larvae:
1) Dissect the 4th instar larva with the help of pointed needles as shown in the video.
2) Hold the posterior end of larva with one needle and pull the anterior part with the second needle.
3) Locate the salivary glands and remove other debris.
********************************************************************
B) Fixation and staining of Salivary glands of Drosophila:
1) Fix the salivary glands with aceto-alcohol fixative for few seconds.
2) Remove the excess fixative with blotting paper.
3) Add two to three drops of Aceto-orcein stain over the salivary glands of Drosophila larvae.
4) Cover the slide with a petri dish or large watch glass and wait for 10 minutes.
5) After 10 min. takeout excess stain by washing the slide with 45% acetic acid.
6) Remove the excess stain and acetic acid with blotting paper.
7) Add one drop of Aceto-orcein stain over the salivary glands of Drosophila larvae.
8) Cover it with a coverslip.
********************************************************************
C) Squash preparation of salivary glands of Drosophila larvae:
1) To squash, the salivary glands under coverslip place the slide between the fold of blotting papers and apply pressure with the thumb over the coverslip and roll it.
2) seal the edges of coverslip with nail polish or DPX.
********************************************************************
D) Observation of squashed salivary glands of Drosophila larvae under the microscope for polytene chromosome.
********************************************************************
#POLYTENECHROMOSOME (Giant chromosome) from #SALIVARYGLAND of Drosophila larvae also know as Fruit fly (Diptera).
One can use Chironomus larvae to perform this experiment. Also, we have demonstrated the procedure of salivary glands dissection or harvesting of salivary glands from Drosophila larvae.
Preparation of Polytene Chromosome from salivary glands of Drosophila Larvae.
E.G.Balbiani (1881) first reported the Polytene chromosomes.
Balbiani rings are exceptionally large puffs on the polytene chromosomes in the dipteran Chironomus salivary glands.
*********************************************************************************************************
polytene chromosome,
chromosome,
dissection,
drosophila,
genetics,
salivary gland,
Polytene Chromosomes in Drosophila salivary glands,polytene Chromosomes,Drosophila salivary glands preparation,polytene Chromosomes in Drosophila practical,salivary glands dissection,polytene chromosome practical,polytene chromosomes in Drosophila,drosophila polytene chromosomes lab,drosophila polytene chromosomes practical,polytene chromosomes drosophila salivary glands,salivary glands of Drosophila larvae,giant chromosome,preparing a wet mount slide