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Short answer
Warthin-Starry staining is a silver impregnation method that makes certain bacteria, including spirochetes, Helicobacter pylori and Bartonella, appear black against a golden-brown tissue background under a light microscope. It shows that bacteria-shaped organisms are present in a section; on its own it does not name the species, and the stain is described in the literature as technically challenging.
Definition and scope
Warthin-Starry (WS) is one of the silver impregnation stains used in histology. A manufacturer of the reagent kit describes it as demonstrating Helicobacter pylori, spirochetes and other Gram-negative bacteria in tissue sections, for examination by light microscopy (Morphisto kit page, checked 2026-10-29). A peer-reviewed case report names it together with the Steiner stain as the silver impregnation methods preferred for detecting Bartonella organisms (Shin et al., Diagnostic Pathology, 2014).
It belongs to the family of special stains, which are applied to tissue when routine hematoxylin and eosin staining does not show the organism of interest. For the wider landscape of stains and what each one targets, see the histological staining guide.
How the stain is used in practice
What the reagent system contains
The manufacturer’s developer kit lists three components: gelatine 5 %, hydroquinone 0.15 % and silver nitrate 1 %. The kit page explains the principle in plain terms: silver ions are reduced by hydroquinone in the presence of gelatin, and the resulting dark silver particles bind to the bacteria so they become visible. Reagent manufacturers publish the working protocol with each kit, and the laboratory’s own standard operating procedure should follow that document rather than this overview.
What a correct result looks like
According to the same kit page, a successful stain gives yellow-brown to golden-brown tissue, black bacteria and dark brown nuclei. That colour description is the quickest read-out check on a control slide: if the background is pale or the bacteria are not black, the run is not behaving as the manufacturer describes.
Where the organisms are looked for
| Target | Specimen where it is looked for | Source |
|---|---|---|
| Helicobacter pylori | Gastric mucosa and the surface epithelium of the gastric glands | Morphisto kit page |
| Bartonella (cat scratch disease) | Areas of necrosis in lymph node tissue; clumps of silver-stained bacilli were seen there in a published case | Shin et al., 2014 |
| Spirochetes and other Gram-negative bacteria | Tissue sections generally | Morphisto kit page |
Warthin-Starry compared with PCR and serology for Bartonella
The most useful practical question is what a positive or negative WS slide can settle. The 2014 case report is open access and sets the three approaches side by side:
| Approach | What the case report says |
|---|---|
| Warthin-Starry or Steiner silver stain | Preferred for detecting Bartonella in tissue, but organisms are variably detectable and the stains are technically challenging. In the reported case, WS showed clumps of bacilli in necrotic areas and the authors called the finding highly suggestive of cat scratch disease but not definitive. |
| PCR | High specificity (100 % in one study) but low sensitivity, ranging from 43 % to 76 %. In the reported case, PCR on formalin-fixed tissue gave the diagnosis. |
| Serology for B. henselae antibodies | Described as the more practical means, but in the reported case the serologic test was negative. |
The comparison shows why a silver stain is read as morphological evidence rather than a final identification: the three methods answer different questions and can disagree in a single patient.
Where it matters for labs and clinics
Three details from the manufacturer’s kit page translate directly into quality-control points for a histology laboratory:
- Final fixation. The kit specifies a final fixation in sodium thiosulphate, and warns that without this step the sections will bleach out after some time. A slide that looked right on the day can fade in the archive if the step was skipped.
- Storage. The kit page gives a storage temperature of 15 to 25 °C. Record the kit lot and storage conditions alongside the run.
- Interpretation. Because organisms are variably detectable, a negative slide carries limited weight by itself. How controls are chosen is a decision for the laboratory’s own validated procedure.
Material for these stains starts as a patient or research specimen; handling and documentation follow the rules for a biospecimen, and archived blocks and slides fall under whatever governs the institution’s tissue bank. Slide preparation itself is covered in the guide to the microscope slide.
Common misunderstandings
A black organism on the slide is not a species identification
Silver impregnation marks bacteria broadly. The kit page lists several groups it can demonstrate, and the case report calls a positive WS result suggestive, not definitive.
A negative slide does not exclude infection
The literature describes the organisms as variably detectable and the stain as technically challenging, so absence of staining carries limited weight by itself.
Stained slides do not stay good automatically
Skipping the thiosulphate fixation step is the example the manufacturer gives of a slide that bleaches over time.
Frequently asked questions
What does Warthin-Starry staining detect?
Per the manufacturer, Helicobacter pylori, spirochetes and other Gram-negative bacteria in tissue sections. In the published literature it is also used to look for Bartonella in lymph node tissue.
What colour are the bacteria with Warthin-Starry?
Black, on a yellow-brown to golden-brown tissue background with dark brown nuclei.
Is Warthin-Starry staining definitive for cat scratch disease?
No. In the cited case report the authors called the finding highly suggestive but not definitive, and PCR on the tissue provided the diagnosis when serology was negative.
Why do Warthin-Starry slides fade?
The manufacturer states that sections bleach out after some time if the final sodium thiosulphate fixation is not carried out.
Sources
- Shin OR, Kim YR, Ban TH, Lim T, Han TH, Kim SY, Seo KJ. A case report of seronegative cat scratch disease, emphasizing the histopathologic point of view. Diagnostic Pathology. 2014;9:62. PMC3983880. Date checked: 2026-10-29.
- Morphisto GmbH. Developer solution kit for Warthin-Starry silver staining, product information page. morphisto.de. Date checked: 2026-10-29.
This page is general information for laboratory and clinical staff. It is not a staining protocol and not individual medical advice.
