[august 2025 mtle] microbiology quality control

temperature checks in the laboratory need to be done _____ on all temperature-dependent equipment

daily

these are examples of temperature-dependent equipment

incubator

autoclave

heating blocks

water bath

refrigerators

freezers

what are the parameters being tested in an incubator?

temperature

CO2

every when are incubators tested for QC?

daily

what are the parameters being tested for QC for a gaspak jar?

anaerobiosis

every when are gaspak jars tested for QC?

each use

what are the parameters being tested for QC in an anaerobe chamber?

anaerobiosis

temperature

humidity

every when are anaerobe chambers being tested for QC?

daily

what is the parameter being tested for QC in a biosafety cabinet?

air flow

who performs the QC for air flow in a BSC?

specialist

frequency of QC for a BSC?

annually

any time hoods are moved

what is being checked in a centrifuge when conducting QC?

RPM

what is the frequency of QC for a centrifuge?

every 6 months

what is being checked in a microscope when conducting QC?

cleanliness

adjusted

what is the frequency of QC of a microscope?

four times per year/quarterly

as needed

what is being checked in a autoclave when conducting QC?

temperature

spore testing

temperature of an autoclave should be checked when?

daily

each load

spore testing of an autoclave should be done when?

weekly

what is being checked in balance when conducting QC?

accuracy of weights

what is the frequency of QC of balance?

annually

all user-prepared culture media should be tested when?

before use

each user-prepared media should be tested with both?

organisms expected to grow and not grow

medium should also be tested for?

sterility

pH

organisms for QC should represent the most or least fastidious?

most

primary plating should be tested with ____ suspensions of specimens

dilute

biochemical media can be tested with _____ media

undiluted

QC records for user-prepared media must be maintained for _____

2 years

commercially prepared media are usually tested by who?

manufacturer

which certain types of commercially-prepared media should be retested by the user?

chocolate agar

selective media for Neisseria and Campylobacter

the laboratory must examine commercially-prepared media for the ff parameters?

moisture

sterility

breakage

appearance

reagents must be tested when?

each day of use

reagents must be tested each day of use with which controls?

positive control

negative control

QC should be performed and documented on all staining procedures at least?

daily

for gram stain, these are the biochemical QC organisms used

Staphylococcus aureus ATCC 25923

Escherichia coli ATCC 25922

non-fastidious, aerobic bacterial organisms can be saved up to ______

1 year

non-fastidious, aerobic bacterial organisms can be saved up to 1 year in which medium?

Trypticase soy agar slants

long-term storage of less than 1 year or aerobes and anaerobes can be accomplished either by which methods?

lyophilization (freeze-drying)

freezing at -70 deg. Celsius

frozen, non-fastidious organisms should be thawed, re-isolated and refrozen every _____?

5 years

frozen, fastidious organisms should be thawed, re-isolated and refrozen every ______?

3 years

stock isolates may be maintained by freezing them in?

10% skim milk

TSB with 15% glycerol

10% horse blood in sterile, screw-cap vials

_____ can be treated as non-fastidious bacterial organisms for maintaining stock cultures

yeasts

_____ can be stored on potato dextrose agar slants at 4 degrees C for 6 months

molds

molds can be stored on which media?

potato dextrose agar slants

molds can be stored on PDA slants at what temperature?

4 degrees Celsius

molds can be stored on PDA slants in the fridge for up to?

6 months to 1 year

for longer-term storage, molds on PDA slants may be over laid with sterile _____

mineral oil

for longer-term storage, molds on PDA slants may be over laid with sterile mineral oil and stored at?

room temperature

acid-fast bacilli may be kept on which culture media?

Lowenstein-Jenson agar slant

acid-fast bacilli may be kept on LJ agar slants at which temperature?

4 degrees Celsius

acid-fast bacilli may be kept on LJ agar slants at 4 deg. C for up to?

1 year

acid-fast bacilli may also be frozen at what temperature?

-70 deg. Celsius

acid-fast bacilli may also be frozen at -70 deg. C in what culture media?

7H9 broth with glycerol

viruses may be stored at which temperature?

-70 degrees Celsius

viruses may be stored in -70 degrees C until?

indefinitely

viruses may be stored indefinitely at -70 degrees C with a cryoprotectant such as ______ or ______?

10% dimethyl sulfoxide

fetal bovine serum

clinical parasitology slides may be preserved indefinitely by adding a drop of _____ and a coverslip.

Permount

clinical parasitology slides prepared in-house should be inspected _____, because the preservation solution may deteriorate and crack over time.

periodically

establishes that the performance parameters of the test are satisfactory

test verification

usually performed when a new method or test is introduced

test verification

results indicate that the test is acceptable for routine use

test verification

results indicate that further verification studies are required

test verification

results indicated that the test is unsuitable for routine use until its performance parameters are verified

test verification

ongoing process that provides information that a test is performing correctly

test validation

components include QC, PT, verification of employee competency and instrument calibration

test validation

results indicate that test continues to be acceptible

test validation

results indicate that further investigation is warranted

test validation

results indicate that immediate corrective action must be undertaken, and the test must be considered unsuitable for routine use until it can be validated

test validation