a_medium (CultureMech:000022)

Overview

External ontology

UTEX:a-plus-medium (source link unavailable) — A+ Medium

Applications

Algae cultivation
Phytoplankton culture
Microalgae research

Notes

UTEX prepares liquid A+ Medium by adding NaCl, MgSO4 x 7 H2O, Na2EDTA x 2 H2O, KCl, CaCl2 x 2 H2O, NaNO3, KH2PO4, and Trizma Base to dH2O, autoclaving, and then adding filter-sterilized A+ Trace Components.

Composition

flowchart LR
    CultureMech_000022["a_medium"]
    ing0_dH2O["dH2O"]
    CultureMech_000022 --> ing0_dH2O
    CHEBI_15377["CHEBI:15377"]
    ing0_dH2O -.-> CHEBI_15377
    ing1_NaCl["NaCl"]
    CultureMech_000022 --> ing1_NaCl
    CHEBI_26710["CHEBI:26710"]
    ing1_NaCl -.-> CHEBI_26710
    ing2_MgSO4_x_7_H2O["MgSO4 x 7 H2O"]
    CultureMech_000022 --> ing2_MgSO4_x_7_H2O
    CHEBI_31795["CHEBI:31795"]
    ing2_MgSO4_x_7_H2O -.-> CHEBI_31795
    ing3_Na2EDTA_x_2_H2O["Na2EDTA x 2 H2O"]
    CultureMech_000022 --> ing3_Na2EDTA_x_2_H2O
    CHEBI_64758["CHEBI:64758"]
    ing3_Na2EDTA_x_2_H2O -.-> CHEBI_64758
    ing4_KCl["KCl"]
    CultureMech_000022 --> ing4_KCl
    CHEBI_32588["CHEBI:32588"]
    ing4_KCl -.-> CHEBI_32588
    ing5_CaCl2_x_2_H2O["CaCl2 x 2 H2O"]
    CultureMech_000022 --> ing5_CaCl2_x_2_H2O
    CHEBI_86158["CHEBI:86158"]
    ing5_CaCl2_x_2_H2O -.-> CHEBI_86158
    ing6_NaNO3["NaNO3"]
    CultureMech_000022 --> ing6_NaNO3
    CHEBI_63005["CHEBI:63005"]
    ing6_NaNO3 -.-> CHEBI_63005
    ing7_KH2PO4["KH2PO4"]
    CultureMech_000022 --> ing7_KH2PO4
    CHEBI_63036["CHEBI:63036"]
    ing7_KH2PO4 -.-> CHEBI_63036
    ing8_Trizma_Base["Trizma Base"]
    CultureMech_000022 --> ing8_Trizma_Base
    CHEBI_9754["CHEBI:9754"]
    ing8_Trizma_Base -.-> CHEBI_9754

Ingredients (9)

#	Ingredient	Concentration	Ontology	Notes
1	dH2O H2O 18.015 g/mol	1000 ML_PER_L	CHEBI:15377 water	UTEX starts the 1 L A+ liquid recipe with approximately 900 mL dH2O.
2	NaCl Cl.Na 58.443 g/mol Fisher S271-500	0.308 MOLAR	CHEBI:26710 sodium chloride	UTEX lists 18 g/L NaCl, for 0.308 M final.
3	MgSO4 x 7 H2O 7H2O.Mg.O4S 246.473 g/mol Sigma 230391	0.02 MOLAR	CHEBI:31795 magnesium sulfate heptahydrate	UTEX lists 5 g/L MgSO4 x 7 H2O, for 0.02 M final.
4	Na2EDTA x 2 H2O C10H14N2O8.2H2O.2Na 372.238 g/mol Sigma ED255	0.08 MILLIMOLAR	CHEBI:64758 EDTA disodium salt dihydrate	UTEX adds 10 mL/L of a 0.3 g/100 mL stock, for 0.08 mM final.
5	KCl Cl.K 74.551 g/mol Fisher P 217	8.05 MILLIMOLAR	CHEBI:32588 potassium chloride	UTEX adds 10 mL/L of a 6 g/100 mL stock, for 8.05 mM final.
6	CaCl2 x 2 H2O Ca.2Cl.2H2O 147.014 g/mol Sigma C-3881	2.52 MILLIMOLAR	CHEBI:86158 calcium chloride dihydrate	UTEX adds 10 mL/L of a 3.7 g/100 mL stock, for 2.52 mM final.
7	NaNO3 NO3.Na 84.994 g/mol Fisher BP360-500	11.8 MILLIMOLAR	CHEBI:63005 sodium nitrate	UTEX adds 10 mL/L of a 10 g/100 mL stock, for 11.8 mM final.
8	KH2PO4 H2O4P.K 136.084 g/mol Sigma P 0662	0.37 MILLIMOLAR	CHEBI:63036 potassium dihydrogen phosphate	UTEX adds 10 mL/L of a 0.5 g/100 mL stock, for 0.37 mM final.
9	Trizma Base C4H11NO3 121.136 g/mol	8.26 MILLIMOLAR	CHEBI:9754 tris	UTEX adds 10 mL/L of a 10 g/100 mL Trizma Base stock adjusted to pH 8.2, for 8.26 mM final.

Preparation

To approximately 900 mL dH2O, add NaCl, MgSO4 x 7 H2O, Na2EDTA x 2 H2O, KCl, CaCl2 x 2 H2O, NaNO3, KH2PO4, and Trizma Base in the UTEX order while stirring.
Bring the total volume to 1 L with dH2O.
Cover and autoclave the medium.
Add filter-sterilized A+ Trace Components.
Allow to cool, then store at refrigerator temperature.

Solutions

A+ Trace Components

Dose: 10 ML_PER_L

Stock composition
Ingredient	Concentration	Notes
dH2O	1000 ML_PER_L	UTEX brings A+ Trace Components to 1 L with dH2O.
H3BO3	3.43 G_PER_L	UTEX lists 3.43 g/L H3BO3 in A+ Trace Components.
ZnCl2	0.0315 G_PER_L	UTEX lists 0.0315 g/L ZnCl2 in A+ Trace Components.
MoO3	0.003 G_PER_L	UTEX lists 0.003 g/L MoO3 in A+ Trace Components.
Vitamin B12	0.0004 G_PER_L	UTEX lists 0.0004 g/L cyanocobalamin in A+ Trace Components.
FeCl3 x 6 H2O	0.14 MILLIMOLAR	UTEX adds 1 mL/L of a 3.89 g/100 mL stock, for 0.14 mM FeCl3 x 6 H2O in A+ Trace Components.
MnCl2 x 4 H2O	0.22 MILLIMOLAR	UTEX adds 1 mL/L of a 4.3 g/100 mL stock, for 0.22 mM MnCl2 x 4 H2O in A+ Trace Components.
CuSO4 x 5 H2O	0.00012 MILLIMOLAR	UTEX adds 1 mL/L of a 0.003 g/100 mL stock, for 0.00012 mM CuSO4 x 5 H2O in A+ Trace Components.
CoCl2 x 6 H2O	0.0005 MILLIMOLAR	UTEX adds 1 mL/L of a 0.012 g/100 mL stock, for 0.0005 mM CoCl2 x 6 H2O in A+ Trace Components.

UTEX adds 10 mL/L filter-sterilized A+ Trace Components.

Target organisms

No target organisms are recorded.

Provenance

Timestamp	Curator	Action	Notes
2026-01-28T00:00:00+00:00	utex-import	Imported from UTEX Culture Collection	Source ID: a-plus-medium, URL: https://utex.org/products/a-plus-medium
2026-03-13T06:18:52.901054Z	culturemech-id-assigner-v1.0	Assigned CultureMech ID	Assigned stable identifier: CultureMech:000022
2026-03-17T19:45:03.872002+00:00	normalize_media_names_to_snake_case.py	NAME_NORMALIZED	Normalized name from "A+ Medium" to "a_medium" for consistent matching
2026-05-16T09:02:56.186289+00:00	migrate_legacy_fields.py	MIGRATED_LEGACY_FIELDS	curation_history.date->timestamp=1; references.reference_id->reference=2; category->lowercase=1
2026-05-16T09:11:01.409343+00:00	migrate_preparation_steps.py	MIGRATED_PREPARATION_STEPS	instruction->action+description for 9 step(s)
2026-08-30T00:58:31.083264+00:00	repair_utex_ingredients.py	REPAIRED_UTEX_COMPOSITION	Restored 10 ingredient name(s) and amount(s) from a re-fetched UTEX capture. The original fetcher read fixed column positions, so the row ordinal was stored as the ingredient name, the component name as the amount, and the Amount column was never read; concentration was then filled in as G_PER_L regardless. Source: https://utex.org/pages/algal-culture-media, captured 2026-08-29T17:46:40.207779.
2026-09-07T00:00:00-07:00	repair_utex_a_bg11_score30.py	RESOLVED_UTEX_A_BG11_SCORE30	UTEX prepares liquid A+ Medium by adding NaCl, MgSO4 x 7 H2O, Na2EDTA x 2 H2O, KCl, CaCl2 x 2 H2O, NaNO3, KH2PO4, and Trizma Base to dH2O, autoclaving, and then adding filter-sterilized A+ Trace Components.