hepes_medium

CultureMech:000171 algae COMPLEX LIQUID
Original name: HEPES Medium

Overview

External ontology
UTEX:hepes-medium (source link unavailable) — HEPES Medium
Applications
  • Algae cultivation
  • Phytoplankton culture
  • Microalgae research
pH
8.2
Notes
UTEX prepares HEPES Medium as an alkaline freshwater recipe at pH 8.2 with nitrate, sulfate, glycerophosphate, KCl, HEPES buffer, P-IV Metal Solution, and B12 and biotin stocks.

Composition

flowchart LR
    CultureMech_000171["hepes_medium"]
    ing0_dH2O["dH2O"]
    CultureMech_000171 --> ing0_dH2O
    CHEBI_15377["CHEBI:15377"]
    ing0_dH2O -.-> CHEBI_15377
    ing1_Ca_NO3_2_x_4_H2O["Ca(NO3)2 x 4 H2O"]
    CultureMech_000171 --> ing1_Ca_NO3_2_x_4_H2O
    CHEBI_86159["CHEBI:86159"]
    ing1_Ca_NO3_2_x_4_H2O -.-> CHEBI_86159
    ing2_MgSO4_x_7_H2O["MgSO4 x 7 H2O"]
    CultureMech_000171 --> ing2_MgSO4_x_7_H2O
    CHEBI_31795["CHEBI:31795"]
    ing2_MgSO4_x_7_H2O -.-> CHEBI_31795
    ing3_Na2glycerophosphate_x_5_H2O["Na2glycerophosphate x 5 H2O"]
    CultureMech_000171 --> ing3_Na2glycerophosphate_x_5_H2O
    CHEBI_15978["CHEBI:15978"]
    ing3_Na2glycerophosphate_x_5_H2O -.-> CHEBI_15978
    ing4_KCl["KCl"]
    CultureMech_000171 --> ing4_KCl
    CHEBI_32588["CHEBI:32588"]
    ing4_KCl -.-> CHEBI_32588
    ing5_HEPES_buffer["HEPES buffer"]
    CultureMech_000171 --> ing5_HEPES_buffer
    CHEBI_42334["CHEBI:42334"]
    ing5_HEPES_buffer -.-> CHEBI_42334

Ingredients (6)

# Ingredient Concentration Ontology Notes
1 dH2O
H2O 18.015 g/mol
1000 ML_PER_L CHEBI:15377
water
 UTEX starts with approximately 950 mL dH2O and brings HEPES Medium to 1 L after adding the non-vitamin components.
2 Ca(NO3)2 x 4 H2O
Ca.4H2O.2NO3 236.146 g/mol
0.5 MILLIMOLAR CHEBI:86159
calcium nitrate tetrahydrate
 UTEX adds 1 mL/L of an 11.8 g/100 mL dH2O stock, for 0.5 mM final.
3 MgSO4 x 7 H2O
7H2O.Mg.O4S 246.473 g/mol
0.16 MILLIMOLAR CHEBI:31795
magnesium sulfate heptahydrate
 UTEX adds 1 mL/L of a 4 g/100 mL dH2O stock, for 0.16 mM final.
4 Na2glycerophosphate x 5 H2O
C3H9O6P 172.073 g/mol
0.16 MILLIMOLAR CHEBI:15978
sn-glycerol 3-phosphate
 UTEX adds 1 mL/L of a 5 g/100 mL dH2O stock, for 0.16 mM final.
5 KCl
Cl.K 74.551 g/mol
0.67 MILLIMOLAR CHEBI:32588
potassium chloride
 UTEX adds 1 mL/L of a 5 g/100 mL dH2O stock, for 0.67 mM final.
6 HEPES buffer
C8H18N2O4S 238.309 g/mol
3.9 MILLIMOLAR CHEBI:42334
HEPES
 UTEX lists 0.94 g/L HEPES buffer, for 3.9 mM final.

Preparation

  1. Add all non-vitamin HEPES Medium components to approximately 950 mL dH2O while stirring continuously.
  2. Adjust the medium to pH 8.2.
  3. Bring the final volume to 1 L with dH2O, then cover and autoclave the medium.
  4. When cooled, add Vitamin B12 and Biotin Vitamin Solution.
  5. Store at refrigerator temperature.

Solutions

P-IV Metal Solution

Dose: 6 ML_PER_L

Stock composition
IngredientConcentrationNotes
dH2O 1000 ML_PER_L UTEX brings P-IV Metal Solution to 1 L with dH2O.
Na2EDTA x 2 H2O 0.75 G_PER_L UTEX lists 0.75 g/L Na2EDTA x 2 H2O, 2 mM final, and dissolves it fully before the other P-IV components.
FeCl3 x 6 H2O 0.097 G_PER_L UTEX lists 0.097 g/L FeCl3 x 6 H2O, for 0.36 mM final.
MnCl2 x 4 H2O 0.041 G_PER_L UTEX lists 0.041 g/L MnCl2 x 4 H2O, for 0.21 mM final.
ZnCl2 0.005 G_PER_L UTEX lists 0.005 g/L ZnCl2, for 0.037 mM final.
CoCl2 x 6 H2O 0.002 G_PER_L UTEX lists 0.002 g/L CoCl2 x 6 H2O, for 0.0084 mM final.
Na2MoO4 x 2 H2O 0.004 G_PER_L UTEX lists 0.004 g/L Na2MoO4 x 2 H2O, for 0.017 mM final.
UTEX adds 6 mL P-IV Metal Solution per liter.

Vitamin B12

Dose: 1 ML_PER_L

Stock composition
IngredientConcentrationNotes
dH2O 1000 ML_PER_L UTEX prepares the Vitamin B12 stock in 200 mL HEPES buffer.
HEPES buffer pH 7.8 12 G_PER_L Converted from 2.4 g/200 mL in the UTEX Vitamin B12 stock.
Vitamin B12 0.135 G_PER_L Converted from 0.027 g/200 mL in the UTEX Vitamin B12 stock.
UTEX adds 1 mL Vitamin B12 stock per liter.

Biotin Vitamin Solution

Dose: 1 ML_PER_L

Stock composition
IngredientConcentrationNotes
dH2O 1000 ML_PER_L UTEX prepares the biotin stock in 200 mL HEPES buffer.
HEPES buffer pH 7.8 12 G_PER_L Converted from 2.4 g/200 mL in the UTEX biotin stock.
Biotin 0.025 G_PER_L Converted from 0.005 g/200 mL in the UTEX biotin stock.
UTEX adds 1 mL Biotin Vitamin Solution per liter.

Target organisms

No target organisms are recorded.

Provenance

TimestampCuratorActionNotes
2026-01-28T00:00:00+00:00 utex-import Imported from UTEX Culture Collection Source ID: hepes-medium, URL: https://utex.org/products/hepes-medium
2026-03-13T06:18:53.401429Z culturemech-id-assigner-v1.0 Assigned CultureMech ID Assigned stable identifier: CultureMech:000171
2026-03-17T19:45:04.338436+00:00 normalize_media_names_to_snake_case.py NAME_NORMALIZED Normalized name from "HEPES Medium" to "hepes_medium" for consistent matching
2026-05-16T09:02:56.009979+00:00 migrate_legacy_fields.py MIGRATED_LEGACY_FIELDS curation_history.date->timestamp=1; references.reference_id->reference=2; category->lowercase=1
2026-05-16T09:11:01.212386+00:00 migrate_preparation_steps.py MIGRATED_PREPARATION_STEPS instruction->action+description for 9 step(s)
2026-08-30T00:58:30.825129+00:00 repair_utex_ingredients.py REPAIRED_UTEX_COMPOSITION Restored 8 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.
2026-09-06T00:00:00-07:00 repair_utex_hepes_score35.py RESOLVED_UTEX_HEPES_SCORE35 UTEX prepares HEPES Medium as an alkaline freshwater recipe at pH 8.2 with nitrate, sulfate, glycerophosphate, KCl, HEPES buffer, P-IV Metal Solution, and B12 and biotin stocks.