Kate Evans at 19:35, 11 February 2026

2026-02-11T19:35:06Z

← Older revision		Revision as of 12:35, 11 February 2026
Line 1:		Line 1:
			{{BreadcrumbsNFixation}}

	* [[Page authors\|Page authors]]: [[Christian Furbo Reeder]], [[PRIMO]]		* [[Page authors\|Page authors]]: [[Christian Furbo Reeder]], [[PRIMO]]

Chreaa: Created page with " * Page authors: Christian Furbo Reeder, PRIMO * Responsible curator: Christian Furbo Reeder ---- TOC
{| class="model-ib" ! What is being measured in 1 - 3 words |- | '''Approach:''' immunolabelling |- | '''Context:''' ''in situ or enviroment'', incubation |- | '''Spatial scale:''' |- | '''Temporal scale:''' days, seasons |- | '''Units:''' signal intensity, counts |- | '''Commu..."

2026-02-10T10:10:10Z

Created page with " * Page authors: Christian Furbo Reeder, PRIMO * Responsible curator: Christian Furbo Reeder ---- __TOC__ <div class="model-box"> {| class="model-ib" ! What is being measured in 1 - 3 words |- | '''Approach:''' immunolabelling |- | '''Context:''' ''in situ or enviroment'', incubation |- | '''Spatial scale:''' |- | '''Temporal scale:''' days, seasons |- | '''Units:''' signal intensity, counts |- | '''Commu..."

New page

* [[Page authors|Page authors]]: [[Christian Furbo Reeder]], [[PRIMO]]
* [[Responsible curator|Responsible curator]]: [[User:Chreaa|Christian Furbo Reeder]]
----

__TOC__
<div class="model-box">
{| class="model-ib"
! What is being measured in 1 - 3 words
|-
| '''Approach:''' immunolabelling
|-
| '''Context:''' ''in situ or enviroment'', incubation
|-
| '''Spatial scale:'''
|-
| '''Temporal scale:''' days, seasons
|-
| '''Units:''' signal intensity, counts
|-
| '''Community captured:''' nitrogenase-expressing diazotrophs
|-
| '''Co-measurements:'''
|}
</div>
<div style="clear:both"></div>

== Method Overview ==
Nitrogenase quantification by immunolabelling targets nitrogenase protein subunits using specific antibodies against the NifH protein. Cells are fixed and incubated with primary antibodies that bind nitrogenase, followed by enzyme-labeled secondary antibodies for detection. Immunolabelling can be combined with epifluorescence microscopy, confocal microscopy, or flow cytometry to quantify the presence, abundance, and spatial distribution of nitrogenase-expressing diazotrophs in environmental samples. This approach provides a direct measure of nitrogenase protein presence rather than gene abundance or enzymatic activity.

== Output ==
* Presence and abundance of nitrogenase-positive cells
* Spatial distribution of nitrogenase-expressing diazotrophs
* Relative protein expression levels (method-dependent)

=== Scale of measurement ===
* Protein / cellular level
* Semi-quantitative
* Single-cell to community-level inference

=== Data generated ===
* Fluorescence microscopy images
* Flow cytometry counts (if applicable)
* Signal intensity measurements
* Cell abundance estimates linked to nitrogenase expression

=== Units & currency ===
* Fluorescence intensity (relative units)
* Counts of nitrogenase-positive cells
* Proportion of labeled cells (%)

=== Sample size ===
* Varies by study design
* Includes biological and technical replicates

=== Repositories & databases ===
* No centralized database for nitrogenase immunolabelling data

== Limitations ==
* Requires highly specific and validated antibodies
* Signal intensity can vary with fixation and staining conditions
* Limited taxonomic resolution without complementary methods (e.g., FISH)
* Antibody availability is biased toward well-studied diazotrophs

== Example Applications & Protocols ==

=== Classic examples ===

=== Recent applications ===

Protocols:
* Immunofluorescence staining protocols targeting NifH
* Microscopy-based quantification workflows
* Custom laboratory SOPs optimized for fixation and antibody specificity

=== Common calculations/conversions ===
* Percentage of nitrogenase-positive cells = (labeled cells / total cells) × 100
* Normalization of signal intensity across samples
* Integration with cell counts for community-level estimates

== References ==

[[Category:Main Pages|Model types]]

Nitrogenase quantification - Revision history

Kate Evans at 19:35, 11 February 2026