> ## Documentation Index
> Fetch the complete documentation index at: https://docs.blis.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Samples

> Learn how bLIS tracks biological samples collected for laboratory testing.

## What is a Sample?

A **sample** is the biological material collected from a subject for laboratory testing — such as blood, serum, urine, tissue, or other specimen types. Each sample is linked to an [accession](/concepts/accessions) and can be used for one or more test orders.

## Sample Tracking

bLIS can track a variety of details about each sample. The specific fields available depend on your lab's configuration:

### Standard Fields

* **Sample Type** — The type of biological material (blood, serum, urine, etc.)
* **Tube Type** — The collection container used
* **Collection Timestamp** — When the sample was collected, including timezone
* **Processing Timestamps** — When refrigerated, centrifuged, or frozen
* **Temperature Data** — Storage temperature and type
* **Expiration Date** — For samples with limited shelf life
* **Display ID** — A unique identifier for labeling and tracking

### Custom Fields

Your lab can configure additional custom fields based on your specific needs. For example:

* **Source** — For microbiology samples (wound, blood culture, etc.)
* **Lot Number** — For quality control samples
* **Transfusion Details** — For transfusion medicine workflows

<Note>
  Not all labs use all fields. The fields you see depend on your laboratory's configuration and the type of testing you perform.
</Note>

## Collection Details

Each sample records when and how it was collected:

<CardGroup cols={2}>
  <Card title="Collection Time" icon="clock">
    The exact date and time the sample was collected from the subject, with timezone information for accurate tracking.
  </Card>

  <Card title="Processing Steps" icon="flask">
    Timestamps for refrigeration, centrifugation, and freezing are tracked to maintain chain of custody.
  </Card>
</CardGroup>

## Sample Types and Tubes

Different tests require different sample types and collection tubes. Your lab's available sample types and tube types are configured by your administrator.

**Common examples:**

* **Blood** samples may use EDTA, SST, or Heparin tubes
* **Serum** samples typically use SST (gold top) tubes
* **Urine** samples use sterile containers
* **Tissue** or **culture** samples have specialized containers

The tube type determines which tests can be performed and affects sample stability and handling requirements.

## Linking Samples to Tests

Test orders are linked to specific samples. When creating a test order, you specify which sample to use. This allows:

* Multiple tests on the same sample
* Different tests on different samples from the same accession
* Tracking which sample was used for each result

<Tip>
  You can track multiple samples per accession. For example, a single accession might have both a blood sample and a urine sample, each used for different test orders.
</Tip>

## Related

<CardGroup cols={2}>
  <Card title="Accessions" icon="clipboard" href="/concepts/accessions">
    Learn about the accessions that samples belong to.
  </Card>

  <Card title="Test Orders" icon="vial" href="/concepts/test-orders">
    See how test orders reference samples.
  </Card>
</CardGroup>