Virology Collection

Viral Culture

The choice of specimen for viral culture depends on the organ system involved (respiratory, central nervous system, etc.). The following suggestions are based on clinical symptoms and are meant only to serve as a general guide.

Respiratory infections: nasopharyngeal aspirate, nasopharyngeal swab, throat swab, bronchoalveolar lavage

Exanthems/enanthems: vesicle fluid (aspirate preferred to swab), nasopharyngeal swab, throat swab, stool

CNS: CSF, stool, nasopharyngeal swab, throat swab

Enteric: nasopharyngeal swab, throat swab, stool

Urogenital: urine (adenovirus, cytomegalovirus), urethral swab, cervical swab; urine specimens are useful for detecting congenital cytomegalovirus or rubella virus infections

Ocular: conjunctival swab

Disseminated: blood, tissues

Note: With the exception of suspected arboviral infections, blood is not usually collected from immunocompetent individuals for viral culture; anticoagulated blood is generally collected for the detection of cytomegalovirus viremia in immunocompromised individuals and may be useful for the diagnosis of congenital infections (e.g. cytomegalovirus, rubella).

Anticoagulated Blood:

Hold at room temperature prior to delivery to the laboratory. Do not refrigerate or freeze.

Attempt to schedule collection of blood for viral culture so that the maximum time between collection and delivery to the laboratory is 18 hours.

Deliver to the laboratory by 1 PM.

Chlamydial Culture

Urogenital: urethral swab, cervical swab, vaginal swab (prepubescent/anestrogenic), rectal swab

Respiratory (neonatal): nasopharyngeal aspirate, nasopharyngeal swab

Occular: conjunctival swab

Viral and Chlamydial Culture

Transport Medium and Swabs

M4 Universal Transport Medium suitable for viruses and chlamydia is available from the laboratory. Store at 2–8oC.

Use dacron or rayon swabs with plastic or aluminum shafts; avoid calcium alginate, cotton, and wooden-shafted swabs.


Do not allow swab specimens to dry. Place swabs into transport medium immediately and keep swab tip immersed during transport to the laboratory.

The specimen tube label must include the patient's name and medical record number and should also include the type of specimen and the date and time of collection.

Note: Storage at warm temperatures for extended periods may reduce the sensitivity of viral or chlamydial cultures.
Specimens other than anticoagulated blood.

Place specimens at 2–8oC (refrigerator temperature) prior to delivery to the laboratory. Do not freeze specimens.

Viral and Chlamydial Non Culture (Direct) Assays

Respiratory syncytial virus, Influenza virus type A and B: Test (immunofluorescence)

Specimen: nasopharyngeal aspirate (NPA) or NP swab collected in transport medium as described above for viral and chlamydial culture (see Table 1). The specimen tube label must include the patient's name and medical record number.

Immediate transport and cold storage are not critical unless viral culture is to be performed on the same sample.

Assay is performed daily. Results are available on the day of receipt for samples received by 2:30 PM.

CMV Antigenemia

Indirect Immunofluorescence of cytospin prepared peripheral blood leukocytes.

Collect a minimum of 5ml of EDTA anticoagulated blood (lavender top). Transport at ambient temperature (Do Not Refrigerate) and deliver to laboratory by 1 PM, Monday – Thursday, and by 10 AM on Fridays.

Test is performed Monday – Friday. Turn around time is 24 hours for specimens received Monday through Friday up to 10 AM. Specimens received after 10 AM on Fridays will be completed by the following Monday.

Chlamydia trachomatis and N. Gonnorrhea DNA by PCR.

Female cervical swab, male urethral swab.

Use M4-RT Viral Transport media.

Follow collection protocol as detailed on collection kit.

Transport at ambient temperature.

Limited to adult cervical and male urethral testing only. See Chlamydia Culture for all other testing.

Turn around time. Within 4 days of receipt of specimen.