2.  Proper collection of specimens is important to
maximize the outcome of laboratory tests for
the diagnosis of infectious diseases
 A variety of laboratory tests can be performed
to make a presumptive or definitive diagnosis
so that therapy can begin.

3. TYPES OF SPECIMEN
COLLECTION

4. Blood Culture
 Normally a sterile body fluid.
 Specimens obtained by venipuncture are
preferred over sampling from vascular
catheters unless testing for a central line
infection.
 Timing is determined by the patient's clinical
condition and should be indicated by the
ordering clinician.

5.  Usually collection is spaced over 24 hours.
 Aseptic technique is essential to avoid
contaminating the specimen with organisms
colonizing the skin.
 Cleanse the venipuncture site with 2%
chlorhexidine gluconate or povidone-iodine
and allow to dry. In case of allergy, use 70%
alcohol.

6.  The diaphragm tops of the culture bottles are
not sterile and must be wiped with alcohol
before injection of blood.

7. Urine Culture
 Normally a sterile body fluid.
 A clean-catch midstream urine collection
provides the best method for obtaining a
specimen to detect a UTI
 Patients who are catheterized should have the
specimen withdrawn using a sterile syringe
from the catheter sampling port

8.  Urine specimens must be transported to the
laboratory promptly. If not cultured within 30
mins of collection, urine must be refrigerated and
cultured within 24 hrs.
 Clean-catch midstream urine specimens that have
more than 100,000 colonies of bacteria per mL of
urine may be indicative of infection.
 Other types of urine specimens may be collected,
such as a straight in-and-out catheter specimen or
suprapubic bladder drainage

9. Stool Culture
 Obtained to culture organisms that are not part
of the normal bowel flora
(eg, salmonella, shigella, rotavirus)
 Patient should defecate into a sterilized
container or bedpan. Stool specimens should not
contain urine or water from the toilet bowl.
 Stool specimens can also be obtained directly
from the rectum using a sterile swab.

10. Sputum Culture
 Specimen needs to be from the lower
respiratory tract, not oropharyngeal secretions.
 The laboratory will perform a Gram stain on all
sputum specimens to determine if they are
representative of pulmonary secretions.
 A specimen containing a majority of cells from
squamous epithelium will be rejected.

11.  The most common method of collection is
expectoration from a cooperative patient with a
productive cough
 Early morning is the optimal time to collect
sputum specimens.
 A sputum specimen can be collected in a
sputum trap from patients who have artificial
airways and require suctioning.

12.  If a patient cannot produce sputum, sputum
induction using an aerosol nebulizer may assist
with loosening thickened secretions.
 Bronchoscopy may be required to obtain
sputum if induction fails.

13. Wound Culture
 Specimens are cultured for aerobic and
anaerobic organisms.
 Using a sterile swab supplied by the
laboratory, collect as much exudate as possible
from the advancing margin of the lesion

14.  Avoid swabbing surrounding skin.
 Place the swab immediately in appropriate
transport culture tube and take to the
laboratory.
 Label with the specific anatomic site.

15. Throat Culture
 Use a tongue depressor to hold the tongue
down.
 Carefully yet firmly rub swab over areas of
exudate or over the tonsils and posterior
pharynx, avoiding the cheeks, teeth, and gums.
 Insert swab into packet and follow directions
for handling the transport medium.