(1) SPECIMEN COLLECTION, HANDLING, AND STORAGE

SPECIMEN COLLECTION, HANDLING, & STORAGE

The first step in the laboratory investigation of infectious diseases

• Contamination due to poor collection technique

• Poor specimen quality

• Wrong timing

• Insufficient quantity

• Suboptimal storage

An improperly collected, handled, and stored sample may lead to false negative/positive results:

CLINICAL SPECIMEN

Represents a portion or quantity of human material that is tested, examined or studied to determine the presence or absence of microorganisms or analytes

Trophozoite

A parasites present in your fecal sample or stool sample, you can’t detect it if they come in contact with urine or water.

Helminths

______ are a diverse group of parasitic worms that infect humans and other animals. They include various species such as roundworms (nematodes) and flatworms (trematodes and cestodes).

Anuria

_______ is the absence of urine production. This might affect microscopic analysis. MT must make use of the sample. Use Pasteur pipettes to transfer urine sample to each urine pads of the strips.

Polyuria

______ is when your body produces too much urine.

Nocturia

______ is the need to urinate at night (usually diabetic patients)

Oliguria

_____ is the severe reduction of urine production and is a sign of an underlying disorder.

• Mixing tubes by inversion
• Transporting of specimens

TYPES OF ROUTINE HANDLING

Mixing tubes by inversion

Some tests require gentle inversions of the specimen tube to evenly distribute the additive

Mixing tubes by inversion

Number of inversions depend on the type of additive or anticoagulant, but it is usually 3-10 gentle inversions

Transporting of specimens

Rough handling of specimens might hemolyze the specimens, activate platelets, affect the coagulation, and even break the glass tube

Rough handling of specimens

______________ might hemolyze the specimens, activate platelets, affect the coagulation, and even break the glass tube

activation of coagulation process

Activation of platelets also means

• Avoid spillage of the specimen
• Minimize agitation of the specimen
• Aid in clot formation for serum tubes

Specimen tubes must be transported with the stopper to:

2 inversions

additional __________ are done if sample stands for a long time. It is to redistribute the cells settled at the bottom of the tube)

• Red top (5 for plastic, 0 for glass)

• Gold top with gel (5)

• Light blue top (3-4)

• Orange top with gel (5)

8 is the initial inversions of the tubes except:

TRANSPORT MEDIUM

Allows organisms (pathogens and contaminants) to survive

Non-nutritive

– does not allow proliferation of organisms

to maintain the viability and quality of the sample

Why do we place our specimen in the transport medium?

• Bacteria
• Viruses
• Parasites

What are the suspected pathogen in the media?

Bacteria

________ – Cary Blair for enterics, Amies for other bacteria

Cary Blair

___________ for enterics

Amies

______ for other bacteria

Viruses

_________ – virus transport media (VTM)

Parasites

________ – 10% formalin to preserve morphology of trophozoites

10% formalin

________ are also used to preserve stool sample

Interfering microorganisms may grow together with the target microorganisms/ MTs must choose a test that could differentiate the target microorganism. Some will only allow the proliferation of that particular microorganism. These contain inhibitors

What is the disadvantage of transport medium?

• Body temperature
• Chilled specimen
• Light Sensitive Specimen

TYPES OF SPECIAL HANDLING

Body temperature

• Some specimens will precipitate or agglutinate if allowed to cool below body temp

precipitate or agglutinate

Some specimens will ________ if allowed to cool below body temp

portable heat blocks

The tubes should also be pre-warmed at 37°C using _________ which could hold the temp for 15 minutes

15 minutes

The tubes should also be pre-warmed at 37°C using portable heat blocks which could hold the temp for _______.

Armpit

Natural way to transport is using the ______

• Cold agglutinins (Immunology and Serology)
• Cryofibrinogen (Hematology)
• Cryoglobulins (Hematology)

Examples of Body Temperature:

Chilling

_____ slows the metabolic process

Chilled specimen

Specimen tubes should be completely submerged in a slurry of crushed ice and water

slurry of crushed ice and water

Chilled specimen tubes should be completely submerged in a ______ and ______.

Chilled specimen

Tested immediately or refrigerated

• Angiotensin converting enzyme (ACE)

• ammonia

• glucagon

• lactic acid

• PTH

• pH/blood gas

• pyruvate

Examples of Chilled specimen:

Parathyroid Hormone

PTH

Light sensitive specimen

Exposure to light can affect the result of a specimen (e.g., bilirubin)

aluminum foil or use light-blocking, amber-colored container.

Sample of light sensitive specimen must be wrapped with _______, _______ and ______.

• Bilirubin

• carotene

• Vitamin B2

• Vit. B6

• Vit. B12

• Vit. C

• urine porphyrins

• urine porphobilinogen

Examples of Light sensitive specimen

Porphyria

- is a condition and they are very sensitive to light.

BLOOD SPECIMEN PROCESSING AND REASONS FOR SPECIMEN REJECTION

After collection, specimens are identified, logged or accessioned, sorted by department and type of processing, and evaluated for specimen suitability.

• Specimens not identified properly

• Inadequate volume to complete the test

• Hemolyzed

• Wrong collection tube used

• Outdated tube

• Improper handling/Improper mixing

• Contaminated specimen

• Specimen is insufficient

• Incorrect collection time

• Specimen expose to light

• Procedure did not follow testing time limits

• Delay or error in processing

Any specimen will be rejected for the following reasons:

crenated or like sea urchins under the microscope – called Burr cells

For instance, the CBC is beyond 6 hours the shaped will be _________ or ______.

48 hrs (2 days)- 2-8 degree Celsius

what is the maximum time for the refrigeration of specimen?

Delivery Time Limits

Specimens must be transported to the laboratory immediately after collection.

Routine blood specimen

_____ is expected to reach the lab within 45 minutes

45 minutes

Routine blood specimen is expected to reach the lab within ______.

Centrifugation

_________ of the specimen should be done in an hour

STAT specimens

________ take priority over all other specimens in terms of transportation, processing, and testing.

they are easily evaporate or volatile

STAT test like ketones and potassium are prioritize because?

• potassium

• ketone (volatile) in the urine sample

• cardiac panel (Troponins)

Examples of STAT tests:

1. Directly from EDTA tube in the laboratory

2. Through skin puncture (bedside smear)

What are the two ways in preparing the smears?

• Blood smear from EDTA specimen

• EDTA specimen for CBC

• EDTA specimen for retics count

• Glucose test with sample drawn in sodium fluoride tubes

• Prothrombin time (PT)

• APTT

Other exceptions for Time Limit Exceptions

Blood smear from EDTA specimen

________ – prepared 1 hour from collection

EDTA specimen for CBC

_______ – analyzed within 6 hours but is stable 24 hours from collection if stored at RT

EDTA specimen for retics count

______ – stable for 6 hours at RT and 72 hours if refrigerated

Reticulocytes

- this is the stage of RBC prior to becoming mature
- slightly immature cells

Erythropoietin

What hormone stimulate the bone marrow?

Glucose test with sample drawn in sodium fluoride tubes

_______ – stable for 24 hours at RT but stable up to 48 hours when refrigerated at 2°C-8°C

Prothrombin time (PT)

– stable for 24 hours

APTT

– should be analyzed within 4 hours from collection

• Leave the stoppers on the tube before and during centrifugation
• Tubes should be balanced

Things to remember when spinning samples:

stoppers or nescofilm

the tubes should always be covered by ______ or _____?

Plasma specimens

– centrifuged immediately without delay

Serum specimens

need to be completely clotted (rest for 30 minutes) prior to centrifugation