Printed circuit board heater for an amplification module

An apparatus, comprising:

• a substrate defining an aperture that separates the substrate into a first portion and a second portion;
• a first heating element coupled to the first portion of the substrate;
• the first heating element configured to produce a first thermal output;
• and
• a second heating element coupled to the second portion of the substrate, the second heating element configured to produce a second thermal output, the second thermal output different from the first thermal output.

A method, comprising:

• conveying a sample into a diagnostic device including an amplification module, the amplification module including a flow member and a heater assembly, the flow member defining a flow path, the heater assembly including a substrate, a first heating element, and a second heating element, the heater assembly coupled to the flow member such that the first heating element is between a first portion of the substrate and a first portion of the flow path, and the second heating element is between a second portion of the substrate and a second portion of the flow path, a third portion of the substrate separating the first portion of the substrate and the second portion of the substrate, the third portion of the substrate characterized by a thermal conductivity that is less than a thermal conductivity of the first portion of the substrate;
• and
• actuating the diagnostic device to:
• supply a first current to the first heating element such that the first heating element maintains the first portion of the flow path at a first temperature;
• supply a second current to the second heating element such that the second heating element maintains the second portion of the flow path at a second temperature, the second temperature different from the first temperature;
• and
• produce a flow of the sample within the flow path.