---
title: build_with_prep_noise (latest version)
description: API reference for qiskit_noise_learning.utils.build_with_prep_noise in the latest version of qiskit-noise-learning
source: https://quantum.cloud.ibm.com/docs/en/api/qiskit-noise-learning/generated/utils-build-with-prep-noise
---

# qiskit\_noise\_learning.utils.build\_with\_prep\_noise

`qiskit_noise_learning.utils.build_with_prep_noise(circuit: QuantumCircuit, prep_noise_ref: str = 'prep', prep_modifier_ref: str = '') → tuple[QuantumCircuit, Samplex]`

[GitHub](https://github.com/Qiskit/qiskit-noise-learning/tree/stable/0.2/qiskit_noise_learning/utils/build_with_prep_noise.py)

Build a template circuit with injectable preparation noise.

This function uses the normal samplex build path except adds an additional node for injectable preparation noise at the beginning of the circuit.

**Parameters**

- **circuit** – The annotated circuit to build.
- **noise\_ref** – The name of the reference to the noise map.
- **modifier\_ref** – The name used for the argument to modify the rates of the noise map.

**Returns**

The template circuit and the samplex.

**Raises**

[**ValueError**](https://docs.python.org/3/builtins/exceptions.html#ValueError) – If the circuit does not begin with a left-dressed twirl annotated box.