genetics ospe (not the lap skill) nmu

name this pipetting common error and how to avoid is

loose tip

load the tip with light pressure

name this pipetting common error and how to avoid is

tilting the pipette

use the pipette vertical for aspiration and (20-45) angle for release only

name this pipetting common error and how to avoid is

quick release of plunger

release the plunger slowly to avoid the inaccurate volume and bubbles

name this pipetting common error and how to avoid is

-the plunger is depressed to the second stop and lead to overaspiration

-the plunger depressed only to the first stop then immersed in the sample to aspirate the required volume

1-identify

2-what is the principle of its work

3-what are they used for

1-spin column

2-its a method of nucleic acid extraction that is based on their binding to silica surfaces in the presence of certain salts and under certain ph conditions

3-they are the most common method for dna extraction

components of dna extraction kit 6

proteinase k

lysis solution

wash buffer 1,2 (conc)

elution buffer

spin columns

collecting tubes

steps of dna extraction 4 عنناوين الخطوات بس

lysis

binding

2 wash steps

elution

name this

what is it used for in assessment of dna quality

agerose gel electrophoresis

used for checking the quality of extracted dna

name this

what is it used for in assessment of dna quantity

uv spectrophotometry (nanodrop)

assessment of dna quantity

name the dna amplification technique and

descripe it

PCR

In vitro laboratory technique for rapidly producing millions to billions of copies of a specific segment of DNA

in vitro يعني في تيوب

name the dna amplification technique and

descripe it

cloning of dna

Producing many copies of a gene (DNA segment) in vivo for example, by replicating it in a culture of bacteria

in vivo يعني في كائن حي

pcr reaction components

1) Target DNA

2) Pair of Primers

3) dNTP

4) A Thermostable DNA Polymerase (Taq polymerase)

5) Buffer solution

مش لاقي صوره للسؤال دا بس سهل يجي ومعاه سؤال تاني ب صوره احد ال components وهما في الطريق في باقي الكروت

3 steps of a single PCR cycle

1- denaturation (95)

2-annealing (55)

3-extension (72)

identify

thermal cycler

where the PCR is done

identify

thermal cycler

where the PCR is done

after 20-30 cycles of PCR how many copies are made

millions / billions of copies are formed

After amplification, why the PCR product is analyzed using agarose gel

electrophoresis

to check the size of the DNA fragments produced.

7 applications of PCR

1- detection of infectious agents

2-forensic medicine (طب شرعي يعني)

3-prenatal genetic diagnosis of diseases والجنين في بطن امه يعني

4-detection of genetic polymorphism

5-tissue typing (to test for compatibility before organ transplant)

6-gene therapy

7-study of evolution

name the process

define it

what is it used to

this technique depends on what ?(سؤال مهم )

electrophoresis

its the movement of charged particles under the influence of an electric field cations moves toward cathode anions move towards anode

used to identify and separate biomolecules : nucleic acids or proteins

based on charge and size (lighter molecules move more distance)

electrophoresis apparatus is formed of what parts

power supply

electric leads

casting tray

gel tank

gel combs

cover

identify

anad what are the types

electrophoresis apparatus

types of dna gel electrophoresis

1)agarose gel electrophoresis

2)polycrylamide gel electrophoresis (PAGE)

identify

and mention its properties 3

utilize what ?

placing ?

separates what ?

agarose gel electrophoresis

utilize agarose powder

horizontal

separate chains of larger size

identify

and mention its properties 3

utilize what ?

placing ?

separates what ?

polyrylamide gel electrophoresis

utilize polyacylamide

vertical

separates short chains of dna thtat differ in length by only one nucleotide !! so its very efficient in separation

2 properties of agerose that make it appropriate for electrophoresis

1-liquid when hot and solidifies on cooling

2-agarose is porous allowing for the movemnt of dna and it resembles a sponge with holes

مش لاقي صوره مناسبه بس جا محتوي سلايد كامل!

what is that blue thing and why its used and what type of electrophoresis is this(سؤال مهم )

a coloured loading dye (bromophenol blue) is mixed to dna sample to

Color and increase sample weight/density to help sample loading

Track the DNA migration (color)

dna bands can be visualized by staining with dyes like ?

and what happens then ?

خد بالك فرق كبير بين ال loading dye وال visualization dye

ethidium bromide

it intercalates between the nitrogenous bases of dna and allows visualization of dna bands under ultraviolet light

what does this indicates in the electrophoresis apparatus

it means that electrodes are connecteed,plugged in and that current is flowing

identify this solution and its uses

ethidium bromide dye

visualized DNA bands by intercalating between the nitrogenous bases of DNA

Identify the device and its uses

UV transilluminator

Visualization of DNA bands under ultraviolet light

what is this

and why it is applied

dna ladder its a solution of dna molecules of different lengths used in agarise or acrylamide gel electrophoresis

its applied as a reference to estemate the size of an unknown dna molecule by comparing them to the closest fragment in the ladder

what is karyotype used to ?

in which stage is karyotyping captured

It describes the number & appearance of chromosomes under light microscope

In metaphase stage

identify and write it

normal female karyotype

46,xx

identify and write it

normal male karyotype

46,xy

type of chromosomal abnormality

and write it

and what is its name

numerical chromosomal abnormality

trisomy of chromosome 21 (male or female)

the picture example 47,xx+21

the male with down syndrome karyotype

47,xy+21

down syndrome

type of chromosomal abnormality

gender

syndrome name

karyotype

caused by ?

abnormality in sex chromosome

female

turner syndrome

45,X0

caused by missinf of one X chromosome in females

type of chromosomal abnormality

gender

syndrome name

karyotype

caused by ?

common ?

abnormality in sex chromosomes

male

klienfelter syndrome

47,xxy (male)

caused by an extra x chromosome (XXY)

its the most common chromosomal abnormality in males

Why karyotyping is Performed? Indications of karyotyping

1. Detection of chromosomal abnormalities

2. Gender determination (Identify the sex of a person)

3. Find out the cause of baby's birth defect or disability

4. Find out the cause of infertility

5. Identify genetic problems

Types of Samples used for Karyotyping

1. A blood sample

2. Amniocentesis or chorionic villus sampling procedures

3. Bone marrow or tissue sample collections

where is karyotype captured ?

and is stained by what ?

سؤال مهم

is arrested at metaphase by (colchicine)

By Giemsa stain then photographed

what type of chromosomal abnormality is

structural chromosomal abnormality

duplication

what type of chromosomal abnormality is

structural chromosomal abnormality

deletion

what type of chromosomal abnormality is

structural chromosomal abnormality

inversion

what type of chromosomal abnormality is this

structural chromosomal abnormality

translocation

lysis step needs what and what happens in it

need lysis solution and what happen is lysis of cellular and nuclear membrane so the nuclear content are released

مش مهم صوره

binding step needs what and what happens in it

needs the spin column and what happens is binding of dna to silica gel membrane

2 wash steps need what and what happens in them

need the 1,2 wash buffer what happen is the removal of protein and any impurities or contaminants

elution step needs what and what happens in it

needs elution buffer and what happen is the release of dna from the membrane so pure dna is formed

movement of charged particle direction

cations move towards cathode

anions move towards anode

cathod anode cation aniion charge respectively

cathode negative

anode positive

cation positive ion

anion negative ion

اللي قريبين في الاسم مختلفين في التشارج فا بيروح ل بعض

dna charge and ion name and where does it migrate and what is the colour of the wire that it migrate towards

dna is negatively charged

so its name is an anion and it will migrate to the anode to the positive red wire

agerose gel properties 2

liquid when hot and solidifies on cooling

its porous allowing movement of dna

what is this dna (visualization)

genomic dna

what is this dna (visualization)

PCR product

what is this dna (visualization)

PCR product

how is karyotyping done (extracting cellular dna)

cells are captured during metaphase stage in mitosis by colchicine the chromosomes are highly condensed and arranged at the cell equator

the 3 key features to identify chromosomes

1 size

2 banding pattern

3 centromere position

why karyotyping is formed 5

detection of genetic abnormality

gender determination

find out the cause of baby birth defect or disability

find out the cause of infertility

help identify genetic problems