MEDL 200 - Final Exam Questions and Answers Latest Update 2025
Culture media - Answers Study and identification of pathological microorganisms is
accomplished by growing suspect patient specimens
Transport media - Answers Maintain all bacteria in a viable state and prevent overgrowth of
bacteria
characteristics of transport media - Answers -Semisolid by the addition of agar
-maintain a constant pH, phosphate buffers
-preservative or lack of nutrients , prevent bacteria overgrowth
-swabs placed in transport media should be refrigerated
Nutrient media - Answers Will support the growth of most organisms
Enriched media - Answers Blood/serum have been added to enhance growth
Selective media - Answers Dyes, antibiotics, chemicals that inhibit the growth of most
organisms ( clinically significant microorganisms )
Differential media - Answers Contain substances or indicators that will differentiate one type of
bacteria from another (MAC plate)
Commercial prepared media - Answers 4 degrees Celsius must be protected dehydration
Peptone - Answers Mixture of amino acids from casein, soy meal and gelatin
Sodium chloride - Answers Isotonic, essential to prevent hemolysis in blood agar
Buffers - Answers Help maintain a constant pH from metabolic wastes produced by bacterial
growth
PH indicator - Answers Specific carbohydrates to determine if fermented during bacterial
growth
Agar - Answers Seaweed product
No nutrients
Solid media
Blood - Answers BAP : whole blood
CHOC : lysed blood
sterilizing media - Answers sterile before using, heat sensitive ingredients may be sterilized w/
, steam autoclave
Sterilizing w/ microbiological filters - Answers used to sterilize a heat sensitive ingredient of
culture media
Moist heat - Answers kills microorganisms by coagulation of microbial proteins
steam autoclave - Answers 121 degrees - 15 mins
Jacket - Answers -steam is removed from the chamber but not from the jacket
door - Answers keeps door locked as long as there is pressure
liquids - Answers -provide moisture necessary for coagulation of microbial protein & sterilization
will take place in tightly closed containers w/o admission of steam
-80% filled or less
biohazardous waste - Answers micro cultures are autoclaved first
-rendered non-viable & discard (safer)
loading autoclave - Answers -articles must be loaded w/ space between, solid containers should
be staggered
-empty tubes & glassware are placed on side to allow entry of stream
-container lids are left loose or removed
Histology - Answers study of microscopic structure of tissue
-10%v/v neutral buffered formalin
SA - Answers S- surgical
A- Autopsy
Preparing tissue - Answers 1. Gross dissection
2.Tissue processing
3.Embedding
4.Sectioning
tissue processing - Answers 1.fixation - preserve the microanatomy (10% formalin)
2. dehydration - removal of water / graded alcohol
3. clearing - xylene
Culture media - Answers Study and identification of pathological microorganisms is
accomplished by growing suspect patient specimens
Transport media - Answers Maintain all bacteria in a viable state and prevent overgrowth of
bacteria
characteristics of transport media - Answers -Semisolid by the addition of agar
-maintain a constant pH, phosphate buffers
-preservative or lack of nutrients , prevent bacteria overgrowth
-swabs placed in transport media should be refrigerated
Nutrient media - Answers Will support the growth of most organisms
Enriched media - Answers Blood/serum have been added to enhance growth
Selective media - Answers Dyes, antibiotics, chemicals that inhibit the growth of most
organisms ( clinically significant microorganisms )
Differential media - Answers Contain substances or indicators that will differentiate one type of
bacteria from another (MAC plate)
Commercial prepared media - Answers 4 degrees Celsius must be protected dehydration
Peptone - Answers Mixture of amino acids from casein, soy meal and gelatin
Sodium chloride - Answers Isotonic, essential to prevent hemolysis in blood agar
Buffers - Answers Help maintain a constant pH from metabolic wastes produced by bacterial
growth
PH indicator - Answers Specific carbohydrates to determine if fermented during bacterial
growth
Agar - Answers Seaweed product
No nutrients
Solid media
Blood - Answers BAP : whole blood
CHOC : lysed blood
sterilizing media - Answers sterile before using, heat sensitive ingredients may be sterilized w/
, steam autoclave
Sterilizing w/ microbiological filters - Answers used to sterilize a heat sensitive ingredient of
culture media
Moist heat - Answers kills microorganisms by coagulation of microbial proteins
steam autoclave - Answers 121 degrees - 15 mins
Jacket - Answers -steam is removed from the chamber but not from the jacket
door - Answers keeps door locked as long as there is pressure
liquids - Answers -provide moisture necessary for coagulation of microbial protein & sterilization
will take place in tightly closed containers w/o admission of steam
-80% filled or less
biohazardous waste - Answers micro cultures are autoclaved first
-rendered non-viable & discard (safer)
loading autoclave - Answers -articles must be loaded w/ space between, solid containers should
be staggered
-empty tubes & glassware are placed on side to allow entry of stream
-container lids are left loose or removed
Histology - Answers study of microscopic structure of tissue
-10%v/v neutral buffered formalin
SA - Answers S- surgical
A- Autopsy
Preparing tissue - Answers 1. Gross dissection
2.Tissue processing
3.Embedding
4.Sectioning
tissue processing - Answers 1.fixation - preserve the microanatomy (10% formalin)
2. dehydration - removal of water / graded alcohol
3. clearing - xylene
