Test Methodology

​Phenotypic serotyping

Reflex Testing Criteria

Salmonella isolates are routed for molecular characterization using Whole Genome Sequencing (WGS) for public health surveillance and epidemiologic investigations only (clinical reports are not issued).​

Pre-Approval Required

Approvals only to CA local city/county public health labs and approved clinical reference laboratories

Supplemental Information and Required Form(s)

Form LAB 446 (PDF) "Bacterial Culture for Identification"

The MDL General Electronic Submission Form should be downloaded and opened using a pdf viewer. To download, right-click the link and select "Save link as." If you are unable to open the Form using a pdf viewer, please contact MDL at 510-412-3700 or MDL.Submissions@CDPH.ca.gov​.

Required Specimen Type(s)

Pure Salmonella isolates only

Isolates should be subcultured prior to submission on nonselective nutrient agar (e.g., trypticase soy or heart infusion slant) in tube with leak-proof screw cap closure.

Contaminated cultures may be rejected​

Minimum Volume Required

Viable growth should be present on the subculture.

Specimen Stability

Store isolates at ambient or refrigerated temperature to maintain viability.

Rejection Criteria

• Submissions with insufficient or conflicting labelling 
• Leaking samples 
• Isolates that are non-viable 
• ​Mixed/contaminated cultures

Storage/Transport Conditions

Grow fresh subculture under appropriate conditions on nonselective nutrient agar slant and verify purity prior to shipping. 

Isolates may be stored and shipped under refrigeration or ambient temperature prior to shipping. 

Ship at ambient temperature or on cold packs; do not freeze or send frozen cultures

Transport Medium, if applicable

Not applicable

Specimen Labeling

Two identifiers, including patient full name, and at least one other identifier (specimen accession number, date of birth, medical record number).

Shipping Instructions and Specimen Handling Requirements

Ship isolates at ambient temperature or with cold packs; do not freeze.

Follow the appropriate DOT/IATA approved shipping procedures.

Ensure that culture isolates are sent in tubes containing a screw-top cap that is additionally sealed with parafilm or tape for additional protection against leaking. DO NOT send plated culture.​​

Ship to: 

Turnaround Time

30 calendar days

Interferences & Limitations

Unable to identify if submitted culture is overgrown by bacterial and/or fungal contaminants or if the culture is non-viable.

If mixed serotypes are present in a culture isolate, Salmonella serotyping may only identify predominate serotype.

Reference Range

Not applicable

Additional Information

None

MDL Point of Contact

For questions regarding submissions, please email MDL.Submissions@cdph.ca.gov​ or call the MDL Immunodiagnostics laboratory at 510-412-3913​