GENERAL LABORATORY PROCEDURES, EQUIPMENT USE AND SAFETY CONSIDERATIONS

Question 1

involves all the measures taken by the laboratory worker, laboratory owner, institution and regulatory agencies to eliminate potential harm to human health and well-being.

Answer 1

Laboratory safety

Question 2

Importance of Laboratory safety

Answer 2

to eliminate potential harm to human health and well-being.

Question 3

is a matter of personal responsibility.

Answer 3

safety

Question 4

It is the responsibility of each person in the lab to…: (4)

Answer 4

to know and follow basic laboratory safety rules

to understand how to safely operate equipment

understand the hazards of materials they are working with and

to work to reduce potential risks

Question 5

SAFETY PROCEDURES (4)

Answer 5

Chemical
Ultraviolet light
Electricity
General housekeeping

Question 6

MSDS

Answer 6

Material safety data sheet

Question 7

Describe

Material Safety Data Sheets or
MSDS-

Answer 7

a document that contains
information on the potential
hazards and how to work safely
with the chemical product.

Question 8

• carcinogen
• potential neurotoxin
• can cause severe burns

Answer 8

Ethidium bromide

Acrylamide

Phenol

Question 9

Ethidium bromide -
Acrylamide -
Phenol -

Answer 9

carcinogen

potential neurotoxin

can cause severe burns

Question 10

Material Safety Data Sheets or MSDS.
This information contains…

Answer 10

the chemical name

Chemical Abstracts Service (CAS) number and health hazard
data including first aid treatment

physical data

fire and explosion hazard data

reactivity data

spill or leak procedures

and any special precautions needed when handling the chemical

Question 11

What to do when exposed to UV light?

Answer 11

always wear appropriate eye protection when using UV lamps

Question 12

UV light can cause…?

Answer 12

Eye irritation

Question 13

The voltages used for_electrophoresis are sufficient to cause_______.

What to do?

Answer 13

electrocution

Always turn off the power supply and unplug the leads before removing a gel

Question 14

GENERAL HOUSEKEEPING

Answer 14

• Keep your own area clean
• All solutions and everything
  stored in an incubator, refrigerator, etc. must be labelled.
• Unlabeled material found in the
  refrigerators, incubators, or
  freezers may be destroyed.

Question 15

Preparation of Solutions

Answer 15

A. Calculation of Molar, % and “X” Solutions

B. Preparation of Working Solutions from Concentrated Stock Solutions

C. Steps in Solution Preparation

D. Glassware and Plastic Ware

Question 16

Dirty test tubes,
bacterial contamination and
traces of detergent can….

Answer 16

inhibit reactions or degrade nucleic acid.

Question 17

Glassware should be rinsed with_____ and autoclaved or baked at _____ for ____

Answer 17

distilled water

150 C for 1 hour

Question 18

For experiments with____, glassware and solutions are treated with diethyl-pyrocarbonate to inhibit_____ which
is resistant to autoclaving.

Answer 18

RNA

RNases

Question 19

For experiments with RNA, glassware and solutions are treated with_______ to inhibit RNases which is resistant to_____.

Answer 19

diethyl-pyrocarbonate

autoclaving

Question 20

•______ are turbid and are resistant to many chemicals, like phenol and chloroform
•_________ are clear and not resistant to many chemicals.

Answer 20

Polypropylene tubes

Polycarbonate or Polystyrene tubes

Question 21

• Polypropylene tubes are….

• Polycarbonate or Polystyrene tubes are…

Answer 21

turbid and are resistant to many chemicals, like phenol and chloroform

clear and not resistant to many chemicals.

Question 22

Disposal of Buffers and Chemicals

1. Any contaminated, solidified
   agar or agarose should be
   discarded in the_____, not in the
   ___, and the bottles rinsed well.

Answer 22

trash; sink

Question 23

Disposal of Buffers and Chemicals

2. Any media that becomes
   contaminated should be
   promptly______ before
   discarding it.

Answer 23

autoclaved

Question 24

Disposal of Buffers and Chemicals

3._______ reagents, should be
used in a fume hood and all
organic waste should be
disposed of in a_____, not in _____

Answer 24

Organic

labelled container, not in the
trash or the sink

Question 25

Disposal of Buffers and Chemicals

4.________ is a mutagenic
substance that should be heat
treated before disposal and
should be handled only with
gloves. It should be disposed of
in a______.

Answer 25

Ethidium bromide

labelled container

Question 26

Disposal of Buffers and Chemicals

5. Dirty glassware should be rinsed.
   Bottle caps, stir bars and spatulas
   should not be placed in the bins
   but should be washed with….

Answer 26

hot soapy water,
rinsed well with hot
water, and
rinsed three times with distilled water

Question 27

Disposal of Buffers and Chemicals:

Answer 27

1. Discard contaminated, solidified agar/agarose in the trash, not the sink, and rinse bottles well.
   
   2. Autoclave contaminated media before disposal.
   3. Use organic reagents in a fume hood; dispose of organic waste in labeled containers, not in the trash or sink.
   4. Handle ethidium bromide with gloves, heat-treat before disposal, and discard in a labeled container.
   5. Rinse dirty glassware; wash caps, stir bars, and spatulas with hot soapy water, rinse with hot water, and rinse three times with distilled water.

Question 28

EQUIPMENT (MMVP TAG)

Answer 28

Micropipette
Micro centrifuge
Vortex
pH meter

Thermal cycler
Autoclave
Gel electrophoresis apparatus

Question 29

Most of the experiments
conducted in the laboratory will
depend on your ability to
accurately measure volumes of
solutions using______.

Answer 29

micropipettes

Question 30

is an instrument that measures the potential difference between a reference electrode and a glass electrode, often combined into one combination electrode.

Answer 30

pH meter

Question 31

This instrument amplifies target
nucleic acid sequences into millions
of copies using the polymerase
chain reaction (PCR) technique

Answer 31

Thermal cycler

Question 32

This equipment facilitates the
separation of biomacromolecules,
such as DNA, RNA, or proteins,
based on their molecular size

Answer 32

Gel electrophoresis

Question 33

A device that mixes liquids in
small containers by creating a
_____, or whirlpool, in the
liquid.

Answer 33

vortex

Question 34

A compact laboratory device
that spins liquid samples at
high speeds to separate their
components

Answer 34

Micro-centrifuge

Question 35

physical method for disinfection and sterilization.

They work with a combination of steam, pressure and time. _____ operate at high temperature and pressure in order to kill microorganisms and spores

Answer 35

Autoclaves

Question 36

1. Heavy Metals Promote______

• _______are the chemical links between the sugar and phosphate groups in DNA’s backbone.

• ______(like lead, mercury, or copper) can react with DNA and cause these bonds to break, damaging the DNA structure.

• Why is this important? If these bonds are broken, the DNA strands become fragmented, making the DNA unusable for experiments like PCR or sequencing.

Answer 36

Phosphodiester Breakage

Phosphodiester bonds

Heavy metals

Question 37

2. Free Radicals and Phosphodiester Breakage

• Free radicals are highly reactive molecules formed by chemical reactions or radiation.

• These radicals can attack DNA, breaking the phosphodiester bonds and damaging the backbone.

• Example: Radiation exposure (like X-rays) can generate free radicals in cells.
• Why is this important? Free radical damage can lead to_____, which is a problem in research and contributes to diseases like cancer.

Answer 37

DNA degradation

Question 38

3. UV Light at_____ Causes DNA Damage

• UV light, especially at _____, is absorbed by DNA and causes damage.

• This damage includes the formation of lesions like______, where two thymine bases bond together incorrectly.

• This disrupts the DNA’s structure, causing loss of biological activity (e.g., the DNA can’t replicate or transcribe properly).

• Why is this important? If DNA is exposed to UV light during an experiment, its quality can be ruined.

Answer 38

260 nm

thymine dimers

Question 39

4. Ethidium Bromide and Photooxidation of DNA

• __________is a dye commonly used to visualize DNA under UV light, but it’s also a mutagen.

• When EtBr interacts with DNA in the presence of visible light and oxygen, it causes photooxidation (a chemical reaction that damages DNA).

• This reaction produces oxidation products that lead to phosphodiester bond breakage, further damaging DNA.

• Why is this important? Handle EtBr carefully to avoid degrading your DNA samples and harming yourself, as it’s a mutagen.

Answer 39

Ethidium bromide (EtBr)

Question 40

5. Nucleases and DNA Protection

a) Nucleases on Human Skin

• ______are enzymes that break down DNA or RNA.

• These enzymes are present naturally on human skin. If your fingers touch DNA samples or tools, the enzymes can degrade the DNA.

• Why is this important? Always use gloves and avoid touching DNA samples directly to prevent contamination or degradation.

Answer 40

Nucleases

Question 41

• Storage of DNA in buoyant CsCl2 with_______ in rice (70)

Answer 41

Ethidium ramodes

Question 42

• For long-term storage of DNA, it is best to store in high salt in the presence of high EDTA at____

Answer 42

pH 8.5

Question 43

Storage for DNA
•______ is one of the best and simplest conditions for storing DNA.
•_______ causes extensive single and double strand breakage.
•–______is probably excellent for long-term storage

Answer 43

5 degree C

–20 C 70 C