What is a Part?

A part is a reusable genetic element with a defined biological function. Parts are the building blocks of genetic constructs in Kernel.

Part Types

Parts are categorized by their biological function:

Regulatory Elements

Type	Function	Example
Promoter	Drives transcription initiation	CMV promoter, T7 promoter
5' UTR	Affects translation efficiency	Kozak sequence
3' UTR	Influences mRNA stability	SV40 poly(A) signal
Terminator	Ends transcription	BGH terminator
Enhancer	Increases transcription	CMV enhancer
Insulator	Blocks regulatory interference	CTCF-binding insulator

Coding Sequences

Type	Function	Example
CDS	Protein coding sequence	GFP, lacZ, antibody chains
Signal peptide	Targets protein localization	IgK signal peptide
Tag	Protein purification/detection	His-tag, FLAG-tag

Structural Elements

Type	Function	Example
Origin	DNA replication start	pUC origin, ColE1
Selectable marker	Selection in host cells	Ampicillin resistance
Linker	Connects protein domains	(G4S)3 linker
Seam	Junction between parts	Standard seam sequences

RNA Elements

Type	Function	Example
RBS	Ribosome binding site	Shine-Dalgarno sequence
Ribozyme	RNA with catalytic activity	Hammerhead ribozyme
RNA regulatory	RNA-based regulation	Toehold switch

Part Properties

Each part has:

Required Properties

• Name: Unique identifier

• Type: Functional classification

• Sequence: DNA sequence

Optional Properties

• Description: What the part does

• Organism: Source organism

• Source: Where the part came from (paper, database)

• Attributes: Custom metadata fields

Parts vs. Annotations

Parts are reusable genetic elements with their own identity. Each part:

• Has its own file in your repository

• Contains rich metadata (type, organism, source, description)

• Is searchable across your workspace

• Can be referenced by multiple constructs

• Is designed for reuse across designs

Annotations are simple labels that mark regions within a sequence. They:

• Exist only within the construct they belong to

• Label sequence features for documentation

• Are not searchable as standalone items

• Are not designed for reuse

Use parts for genetic elements you plan to reuse (promoters, genes, terminators). Use simple annotations for one-off labels or features imported from GenBank files that you don't need to track separately.

Part Visualization

In the construct editor, parts appear as:

• Schematic symbols: Standardized icons showing part type and direction

• Colored regions: In the sequence viewer, parts are highlighted

• Labels: Part names appear in the schematic view

Next Steps

• Creating Parts — Add parts to your library

• Part Library — Access public part collections

• Creating Constructs — Use parts in designs