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

# IgG

> Full-length antibody format with two antigen-binding sites

IgG is the standard full-length antibody format used in most therapeutic monoclonal antibodies, featuring two identical antigen-binding sites.

<CardGroup cols={2}>
  <Card title="Size" icon="ruler">
    \~150 kDa
  </Card>

  <Card title="Valency" icon="link">
    Bivalent (2 binding sites)
  </Card>

  <Card title="Half-life" icon="clock">
    \~3 weeks in humans
  </Card>

  <Card title="Production" icon="flask">
    Mammalian cells
  </Card>
</CardGroup>

## Structure Components

* **Heavy chains** (2x \~50 kDa) + **Light chains** (2x \~25 kDa)
* **Fc region** - Enables effector functions
* **Fab regions** - Two identical antigen-binding sites
* **Hinge region** - Provides flexibility

<Tabs>
  <Tab title="IgG1">
    Most common therapeutic format with strong effector functions
  </Tab>

  <Tab title="IgG2">
    Reduced effector functions, suitable for some therapeutics
  </Tab>

  <Tab title="IgG4">
    Minimal effector functions when immune activation is undesired
  </Tab>
</Tabs>

<Note>
  IgG represents the gold standard for therapeutic antibodies due to its bivalent binding, long half-life, and well-characterized manufacturing processes.
</Note>