Page 1 of 75
“Mock Exam I and II 2026 ”LATEST EXAM 2026 – 2027
SOLVED QUESTIONS & ANSWERS VERIFIED 100%
GRADED A+ (LATEST VERSION) WELL REVISED 100%
GUARANTEE PASS
A lysed sample is received in the laboratory for evaluation of thalassemia by
Southern blot analysis. The technologist should:
a) request a new sample immediately
b) snap freeze the sample to remove hemoglobin
c) homogenize the sample prior to extraction
d) increase volumes of reagents for restriction digestion.
a) request a new sample immediately
Large quantities of high quality DNA can not be extracted from lysed samples.
Extracted RNA samples should be shipped:
a) frozen, on dry ice
b) at ambient temperature
c) in EDTA anticoagulant
d) spotted on Guthrie cards
a) frozen, on dry ice
RNA samples are easily degraded and should be stored and shipped frozen
In a Southern blot procedure, which of the following wash conditions is LEAST
likely to affect stringency?
a) Temperature
b) pH
c) Salt concentration
d) Time
, Page 2 of 75
b) pH
Salt concentration, temperature, and time will increase or decrease stringency
Which of the following actions should NOT be done to a nylon membrane
containing DNA after a Southern transfer?
a) UV crosslink the DNA to the membrane
b) Bake the membrane at 80 degrees C overnight
c) Allow a positively charged membrane to air-dry overnight
d) Place the membrane on a UV transilluminator for 10 minutes
b) Bake the membrane at 80 degrees C overnight
After Southern transfer, DNA is immobilized on a membrane by baking at 80 degrees
C for 1-2 hours.
Which of the following information is included in MSDS?
a) Catalog number
b) Product price
c) Waste disposal methods
d) Chemical concentration
c) Waste disposal methods
MSDS sheets include information such as physical data, toxicity, health effects, first
aid, reactivity, storage, disposal, protective equipment, and spill handling
procedures.
Instruments used for initiation of amniocyte cultures are best sterilized by:
a) wiping with sterilized distilled water.
b) cleaning with sterile 70% ethanol swabs
c) placing in dry heat at 160 degrees C for a minimum of 1 hour
d) machine-washing four complete changes of water
c) placing in dry heat at 160 degrees C for a minimum of 1 hour
Instruments should be heat sterilized
How much Tris base (MW= 121.1) would be required to make 4 liters of Tris-
EDTA buffer that is 15mM Tris?
a) 0.7266 grams
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b) 0.1211 grams
c) 1.8165 grams
d) 7.266 grams
d) 7.266 grams
0.015 mol/L 121.1g/mol 4L = 7.266g
Which of the following compositions of gels would allow for the efficient
separation of linear DNA molecules in the range of 100 to 300 base pairs in
length?
a) 0.3% agarose
b) 1.0% agarose
c) 1.0% polyacrylamide
d) 8.0% polyacrylamide
d) 8.0% polyacrylamide
Small base pair size fragments are best separated on 8.0% polyacrylamide, the
other concentrations are too low to work with. Also, remember that agarose is good
for sizes 200-50,000 bp and polyacrylamide is good for 200-1000 bp.
Calf intestinal phosphatase is used during the cloning procedure to:
a) phosphorylate cloned DNA
b) inhibit transformation of E. coli
c) prevent vector re-ligation
d) repair ss nicks in the plasmid
c) prevent vector re-ligation
Enzyme catalyzes the 5' phosphate group's removal from DNA. DNA fragments
which lack the 5' phosphoryl termini cannot self ligate
Which of the following actions will bind DNA to a positively charged nylon
membrane?
a) Incubation at 37 degrees C for 15 minutes
b) Baking at 80 degrees C for 2 hours
c) Treatment with 0.5M sodium hydroxide
d) Treatment with acidic buffer
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b) Baking at 80 degrees C for 2 hours
DNA is immobilized on a membrane by baking at 80 degrees C for 1-2 hours
Undigested high quality DNA appears on a test gel as:
a) a single band
b) a smear
c) two bands below lambda phage
d) multiple bands
a) a single band
Undigested high molecular weight DNA should appear as a single band. A smear
would be seen degraded or highly digested DNA and multiple bands would be seen
with digested DNA.
Which of the following actions is most appropriate for decontaminating the
work surface after large scale preparation of E. coli?
a) Swab with 70% methanol
b) Irradiate with 354 nm ultraviolet light
c) Disinfect with 10% hypochlorite
d) Clean up with DNase Away
c) Disinfect with 10% hypochlorite
10% bleach is best for killing bacteria
Compression on a sequencing gel is:
a) Diagnostic of a point mutation
b) Evidenced as 'smiling' in the lanes
c) An indication of a palindromic sequence
d) An anomalous hybridization of silver stain
c) An indication of a palindromic sequence
Long palindromic sequences (those that read the same in both directions) can result
in gel compression
Which of the following techniques is most appropriate for preparing high
purity reagents for use in cloning procedures?
a) Autoclaving in tightly capped sterile bottles
“Mock Exam I and II 2026 ”LATEST EXAM 2026 – 2027
SOLVED QUESTIONS & ANSWERS VERIFIED 100%
GRADED A+ (LATEST VERSION) WELL REVISED 100%
GUARANTEE PASS
A lysed sample is received in the laboratory for evaluation of thalassemia by
Southern blot analysis. The technologist should:
a) request a new sample immediately
b) snap freeze the sample to remove hemoglobin
c) homogenize the sample prior to extraction
d) increase volumes of reagents for restriction digestion.
a) request a new sample immediately
Large quantities of high quality DNA can not be extracted from lysed samples.
Extracted RNA samples should be shipped:
a) frozen, on dry ice
b) at ambient temperature
c) in EDTA anticoagulant
d) spotted on Guthrie cards
a) frozen, on dry ice
RNA samples are easily degraded and should be stored and shipped frozen
In a Southern blot procedure, which of the following wash conditions is LEAST
likely to affect stringency?
a) Temperature
b) pH
c) Salt concentration
d) Time
, Page 2 of 75
b) pH
Salt concentration, temperature, and time will increase or decrease stringency
Which of the following actions should NOT be done to a nylon membrane
containing DNA after a Southern transfer?
a) UV crosslink the DNA to the membrane
b) Bake the membrane at 80 degrees C overnight
c) Allow a positively charged membrane to air-dry overnight
d) Place the membrane on a UV transilluminator for 10 minutes
b) Bake the membrane at 80 degrees C overnight
After Southern transfer, DNA is immobilized on a membrane by baking at 80 degrees
C for 1-2 hours.
Which of the following information is included in MSDS?
a) Catalog number
b) Product price
c) Waste disposal methods
d) Chemical concentration
c) Waste disposal methods
MSDS sheets include information such as physical data, toxicity, health effects, first
aid, reactivity, storage, disposal, protective equipment, and spill handling
procedures.
Instruments used for initiation of amniocyte cultures are best sterilized by:
a) wiping with sterilized distilled water.
b) cleaning with sterile 70% ethanol swabs
c) placing in dry heat at 160 degrees C for a minimum of 1 hour
d) machine-washing four complete changes of water
c) placing in dry heat at 160 degrees C for a minimum of 1 hour
Instruments should be heat sterilized
How much Tris base (MW= 121.1) would be required to make 4 liters of Tris-
EDTA buffer that is 15mM Tris?
a) 0.7266 grams
, Page 3 of 75
b) 0.1211 grams
c) 1.8165 grams
d) 7.266 grams
d) 7.266 grams
0.015 mol/L 121.1g/mol 4L = 7.266g
Which of the following compositions of gels would allow for the efficient
separation of linear DNA molecules in the range of 100 to 300 base pairs in
length?
a) 0.3% agarose
b) 1.0% agarose
c) 1.0% polyacrylamide
d) 8.0% polyacrylamide
d) 8.0% polyacrylamide
Small base pair size fragments are best separated on 8.0% polyacrylamide, the
other concentrations are too low to work with. Also, remember that agarose is good
for sizes 200-50,000 bp and polyacrylamide is good for 200-1000 bp.
Calf intestinal phosphatase is used during the cloning procedure to:
a) phosphorylate cloned DNA
b) inhibit transformation of E. coli
c) prevent vector re-ligation
d) repair ss nicks in the plasmid
c) prevent vector re-ligation
Enzyme catalyzes the 5' phosphate group's removal from DNA. DNA fragments
which lack the 5' phosphoryl termini cannot self ligate
Which of the following actions will bind DNA to a positively charged nylon
membrane?
a) Incubation at 37 degrees C for 15 minutes
b) Baking at 80 degrees C for 2 hours
c) Treatment with 0.5M sodium hydroxide
d) Treatment with acidic buffer
, Page 4 of 75
b) Baking at 80 degrees C for 2 hours
DNA is immobilized on a membrane by baking at 80 degrees C for 1-2 hours
Undigested high quality DNA appears on a test gel as:
a) a single band
b) a smear
c) two bands below lambda phage
d) multiple bands
a) a single band
Undigested high molecular weight DNA should appear as a single band. A smear
would be seen degraded or highly digested DNA and multiple bands would be seen
with digested DNA.
Which of the following actions is most appropriate for decontaminating the
work surface after large scale preparation of E. coli?
a) Swab with 70% methanol
b) Irradiate with 354 nm ultraviolet light
c) Disinfect with 10% hypochlorite
d) Clean up with DNase Away
c) Disinfect with 10% hypochlorite
10% bleach is best for killing bacteria
Compression on a sequencing gel is:
a) Diagnostic of a point mutation
b) Evidenced as 'smiling' in the lanes
c) An indication of a palindromic sequence
d) An anomalous hybridization of silver stain
c) An indication of a palindromic sequence
Long palindromic sequences (those that read the same in both directions) can result
in gel compression
Which of the following techniques is most appropriate for preparing high
purity reagents for use in cloning procedures?
a) Autoclaving in tightly capped sterile bottles
