MODULE 3
TEMA 1 : BIOLOGICAL SAMPLES
DR. y MTRO. LUIS CARLOS GUARDADO

What is a biological sample in humans?
In general, biological material is considered to be any material of
human origin, such as excretions, secretions, cell lines, tissues,
tissue fluids (blood, plasma, serum, saliva) and isolates of
microorganisms (cultures).

BIOLOGICAL SAMPLES
■ They are substances capable of being analyzed to reach a
■ Confirmatory diagnosis.
■ Collected by the nursing staff, other specific samples by the Doctor.
Examples:

ANALYSIS PROCESS
• Request for analysis
• Patient preparation
• Collection of biological material
• Transport and conservation
• Calibration of measurement processes
• Processing of samples Obtaining results
• Evaluation of the result
• Emission of the result
• Interpretation of the result
• Interpretation of the result by the Physician
PREANALÍTICA
POST ANALÍTICA
ANALÍTICA

Pre analytics
From the moment the doctor prepares
the analysis request until the sample is
received by a laboratory to be processed.
Obtaining a biological sample of Quality:
Representative to report the status of a
patient at a given time.
Physician makes the request
Nursing obtains the sample
Transport to lab

Analytics
■ The sample is studied by clinical technicians or microbiologists
Pending the results

Post analytics
■ The result reaches the
doctor
■ Diagnostic
■ Treatment

Rules for collecting samples
■ All samples must be accompanied by a medical order.
■ The medical order must go: sample type, name, clinical data, dates, # bed, # SS and
HxClx. Dx, clinical presumption.
■ Universal precautionary measures for biological waste (hygiene, barrier, handling of
sharp punctures, etc.)
■ Prepare materials and obtain sample in conditions of asepsis Informed consent
■ Obtained the sample label it and take measures to ensure the conservation of it
■ Urgent YES or NO Fasting: 8 – 12 hours ********Carbamazepine, Ac. Valproico, DFH:
fasting without taking medication.

Sample types
■ Urine
■ Blood
■ Stool
■ Vomit
■ Sputum (phlegm)
■ CSF
■ Gastric/duodenal (SNG) content
■ Seminal fluid (semen)
■ Exudates:
■ Nasal
■ Pharyngeal
■ Conjunctival
■ Otic
■ Urethral
■ Vaginal
■ Wounds

URINE SAMPLE
A urinalysis. It is often done to assess and determine if there is a urinary tract
infection, kidney problems, or diabetes.
A urinalysis consists of analyzing:
• Your color
• Your appearance (if it is clear or cloudy)
• Your smell The level of acidity (pH)
• If there are substances that are not normally in the urine, such as blood,
excess protein, glucose, ketones, and bilirubin
• If there are cells, crystals and urinary cylinders (proteins in the form of a
tube)
• If you have bacteria or other germs

Analysis of the urine sample
■ It is a routine examination
■ Great importance for diagnosis
■ Types of tests Urinary analysis: PH, density, proteins,
glucose, bacteria
■ Uro culture: Sterile sample Diuresis 12 / 24 hours :
Proteinuria 24 hours

Urine Sample Collection
■ Explain to the patient the procedure to be performed and request
collaboration,
■ If the patient can perform the collection by himself, explain,
■ If the patient cannot: put on gloves and place the bottle on the patient,
■ Fill the pot up to 3/4 of its capacity.
■ Bottle is capped and properly identified with patient labels
■ collect the materials,
■ Write down the incidents and procedure,
■ avoid contamination.
■ https://www.youtube.com/watch?v=ucImR30QNfs
■ https://www.youtube.com/watch?v=d8MI3H7IGQ0

BLADDER CATHETER SAMPLING

Urocultivo
■ Procedimiento

Blood samples
■ Depending on the type of analysis the doctor wants, it
can be capillary blood and venous blood
■ https://www.youtube.com/watch?v=QmhtzmfPa40

Capillary Blood Procedure
■ Explain to the patient the procedure to follow
■ wash our hands
■ Choose the area and give a massage
■ Clean the area with povidone iodine.
■ With the lancet make the puncture
■ collect sample
■ Press for hemostasis
■ Pick up material
■ take off gloves
■ annotate procedures

Arterial Blood Procedure
■ Blood gases
■ https://www.youtube.com/watch?v=q57PQUHKTeQ

VENOPUNCTION PROCEDURE
Most of the time, the blood is drawn from a vein located on the inside of the
elbow or the back of the hand.
• The site is cleaned with a disinfectant (antiseptic).
• An elastic band is placed around the upper arm in order to apply pressure to
the area. This causes the vein below to fill with blood.
• A needle is inserted into the vein.
• The blood is collected in an airtight vial or tube attached to the needle.
• The elastic band is removed from the arm.
• The needle is removed and the site is covered with gauze or a dressing to
stop the bleeding.

Venous blood procedure
Puncture: waiting until the disinfectant has dried; the angle of the
needle is usually between 30-40º; the bezel of the needle will go
upwards, to prevent it from slipping over the epidermis. It should not be
punctured over the vein.

EXTRACTION ORDER
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Blood culture
■ https://www.youtube.com/watch?v=4xlZscQQxkE

Stool sample
■ Stool culture
■ Investigate if there is growth of bacteria
■ Existence of occult blood

Process
■ Explain the procedure to the patient
■ wash our hands put on gloves
■ Place the bedpan and ask him to defecate in it
■ With the depressor, take a sample and put it in the bottle and close the bottle
immediately
■ Accommodating and grooming the patient
■ collect the materials
■ Take off our gloves and wash our hands
■ annotate the procedure

Muestra de Vomito
Process:
■ Explain to the patient and procedure
■ Wash our hands and put on gloves
■ pick up vomit
■ If not conscious, place them in lateral decubitus to avoid aspiration.
■ labeled container
■ Clean the patient
■ take off our gloves
■ annotate and point

Sputum Samples
■ Sputum: discharge from the nose, throat, or bronchial tubes
■ Expectoration plus cough
■ Microscopic analysis: cells, germs
■ Macroscopic analysis: color, smell, appearance, consistency
■ Collect this sample first thing in the morning
■ Sputum is not the same as saliva

Process
■ Conscious Patient
■ Explain the procedure to the patient and request collaboration
■ Wash our hands and put on gloves
■ Instruct the patient to wash their mouth to avoid contamination.
■ Ask him to inspire 3 times and in the last cough forcefully to expel bronchial
content
■ Bring the sterile bottle closer to the patient and close it
■ label the jar
■ annotate the procedure

Cerebrospinal fluid sample
Lumbar puncture (spinal tap): A lumbar puncture is done in the lower back, in the
lumbar region. During a lumbar puncture, a needle is inserted between two lumbar
bones (vertebrae) to remove a sample of cerebrospinal fluid
• It is a technique that carries risk to the patient.
• Between the subarachnoid space of the spinal canal.
• Lumbar puncture
• Between the 3rd and 4th lumbar vertebra

Process
■ Explain the procedure to the patient
■ wash our hands
■ Place the patient in the fetal position
■ Put on sterile gloves Clean asepsis antisepsis
■ The doctor will perform the puncture
■ Cover with a dressing
■ Collect material and leave in supine position
■ Do not raise your head for 3 hours

Gastric duodenal content
sample

Seminal fluid sample
■ It is used for the study of infertility and vasectomy
■ To study quantity, shape, mobility number
■ The sample is obtained 3 days of sexual abstinence

Exudate Sample
■ Exudate : expel
■ Cells that slowly expel fluid through cell membranes through small openings in
the skin and mucosa

Process
■ Explain to the patient the procedure to be
performed
■ Wash our hands and put on gloves
■ perform hygiene
■ Pass the swab gently
■ Place the swab inside the transport tube
■ label it correctly
■ Pick up material
■ accommodate the patient
■ annotate procedure

Nasal exudate
■ Rotation

Pharyngeal exudate
■ Depressor

Wound exudates

Sample transport
■ Hand delivery
■ Pneumatictubes