Overview
- External ontology
- UTEX:8-ppt-f-2-medium (source link unavailable) — 8 ppt F/2 Medium
- Applications
-
- Algae cultivation
- Phytoplankton culture
- Microalgae research
- Notes
- UTEX prepares 8 ppt F/2 Medium by diluting seawater to 8 ppt and then adding the standard F/2 nutrient, trace-metal, and vitamin stocks.
Composition
flowchart LR
CultureMech_000021["8_ppt_f_2_medium"]
ing0_Seawater_diluted_to_8_ppt["Seawater diluted to 8 ppt"]
CultureMech_000021 --> ing0_Seawater_diluted_to_8_ppt
ing1_NaNO3["NaNO3"]
CultureMech_000021 --> ing1_NaNO3
CHEBI_63005["CHEBI:63005"]
ing1_NaNO3 -.-> CHEBI_63005
ing2_Sodium_dihydrogenphosphate_monohydrate["Sodium dihydrogenphosphate monohydrate"]
CultureMech_000021 --> ing2_Sodium_dihydrogenphosphate_monohydrate
CHEBI_114249["CHEBI:114249"]
ing2_Sodium_dihydrogenphosphate_monohydrate -.-> CHEBI_114249
ing3_Na2SiO3_9H2O["Na2SiO3•9H2O"]
CultureMech_000021 --> ing3_Na2SiO3_9H2O
CHEBI_132108["CHEBI:132108"]
ing3_Na2SiO3_9H2O -.-> CHEBI_132108
Ingredients (4)
| # | Ingredient | Concentration | Ontology | Notes |
|---|---|---|---|---|
| 1 | Seawater diluted to 8 ppt |
ENVO:00002149
sea water
|
Seawater is used to bring the recipe to its stated 1 L total volume. Its total input volume is not independently quantified; no fixed solvent concentration is asserted. Prepare seawater at 8 ppt; the initial charge is approximately 950 mL. | |
| 2 |
NaNO3
NO3.Na 84.994 g/mol
Fisher BP360-500
|
880 MICROMOLAR |
CHEBI:63005
sodium nitrate
|
UTEX adds 1 mL per liter of a 7.5 g/100 mL dH2O stock. |
| 3 |
Sodium dihydrogenphosphate monohydrate
H2O.H2O4P.Na 137.991 g/mol
MCIB 742
|
36 MICROMOLAR |
CHEBI:114249
sodium dihydrogenphosphate monohydrate
|
UTEX adds 1 mL per liter of a 0.5 g/100 mL dH2O stock. |
| 4 |
Na2SiO3•9H2O
9H2O.2Na.O3Si 284.198 g/mol
Sigma 307815
|
106 MICROMOLAR |
CHEBI:132108
sodium silicate nonahydrate
|
UTEX adds 1 mL per liter of a 3 g/100 mL dH2O stock, for 106 uM final. |
Preparation
- To approximately 950 mL non-pasteurized seawater at 8 ppt, add the F/2 nutrient stocks and Trace Metals Solution while stirring.
- Bring the total volume to 1 L with non-pasteurized seawater at 8 ppt.
- Cover and autoclave the medium.
- When cooled, add the sterile vitamin stocks.
- Store at refrigerator temperature.
Solutions
Trace Metals Solution
Dose: 1 ML_PER_L
| Ingredient | Concentration | Notes |
|---|---|---|
| dH2O | Water is used to bring Trace Metals Solution to 1 L total; its input amount is not separately quantified. | |
| ZnSO4 x 7 H2O | 0.023 G_PER_L | Converted from 23 mg/L in the UTEX Trace Metals Solution recipe. Evidence supports the stock mass column only; the source molarity column is discrepant and is not used to infer a corrected molarity or receiving-medium concentration. |
| MnSO4 x H2O | 0.152 G_PER_L | Converted from 152 mg/L in the UTEX Trace Metals Solution recipe. Evidence supports the stock mass column only; the source molarity column is discrepant and is not used to infer a corrected molarity or receiving-medium concentration. |
| Na2MoO4 x 2 H2O | 0.0073 G_PER_L | Converted from 7.3 mg/L in the UTEX Trace Metals Solution recipe. Evidence supports the stock mass column only; the source molarity column is discrepant and is not used to infer a corrected molarity or receiving-medium concentration. |
| CoSO4 x 7 H2O | 0.014 G_PER_L | Converted from 14 mg/L in the UTEX Trace Metals Solution recipe. Evidence supports the stock mass column only; the source molarity column is discrepant and is not used to infer a corrected molarity or receiving-medium concentration. |
| CuCl2 x 2 H2O | 0.0068 G_PER_L | Converted from 6.8 mg/L in the UTEX Trace Metals Solution recipe. Evidence supports the stock mass column only; the source molarity column is discrepant and is not used to infer a corrected molarity or receiving-medium concentration. |
| Fe(NH4)2(SO4)2 x 6 H2O | 4.6 G_PER_L | UTEX lists 4.6 g/L in the Trace Metals Solution recipe. Evidence supports the stock mass column only; the source molarity column is discrepant and is not used to infer a corrected molarity or receiving-medium concentration. |
| Na2EDTA x 2 H2O | 4.4 G_PER_L | UTEX lists 4.4 g/L in the Trace Metals Solution recipe. Evidence supports the stock mass column only; the source molarity column is discrepant and is not used to infer a corrected molarity or receiving-medium concentration. |
UTEX adds 1 mL of this prepared stock per liter of 8 ppt F/2 Medium; composition values describe the stock, not final-medium concentrations. The linked stock table has an unresolved mass/molarity discrepancy; its mass column is preserved and no molarity is inferred.
Vitamin B12
Dose: 1 ML_PER_L
| Ingredient | Concentration | Notes |
|---|---|---|
| dH2O | The source prepares 200 mL HEPES buffer before adding the vitamin. It does not separately quantify pure-water input; no fixed water concentration is asserted. | |
| HEPES buffer pH 7.8 | 12 G_PER_L | Converted from 2.4 g/200 mL in the UTEX Vitamin B12 stock. |
| Cyanocobalamin | 0.135 G_PER_L | Converted from 0.027 g/200 mL in the UTEX Vitamin B12 stock. |
UTEX adds 1 mL of this prepared stock per liter of 8 ppt F/2 Medium; composition values describe the stock, not final-medium concentrations.
Biotin Vitamin Solution
Dose: 1 ML_PER_L
| Ingredient | Concentration | Notes |
|---|---|---|
| dH2O | The source prepares 200 mL HEPES buffer before adding the vitamin. It does not separately quantify pure-water input; no fixed water concentration is asserted. | |
| 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 of this prepared stock per liter of 8 ppt F/2 Medium; composition values describe the stock, not final-medium concentrations.
Thiamine Vitamin Solution
Dose: 1 ML_PER_L
| Ingredient | Concentration | Notes |
|---|---|---|
| dH2O | The source prepares 200 mL HEPES buffer before adding the vitamin. It does not separately quantify pure-water input; no fixed water concentration is asserted. | |
| HEPES buffer pH 7.8 | 12 G_PER_L | Converted from 2.4 g/200 mL in the UTEX thiamine stock. |
| Thiamine hydrochloride | 0.335 G_PER_L | Converted from 0.067 g/200 mL in the UTEX thiamine stock. |
UTEX adds 1 mL of this prepared stock per liter of 8 ppt F/2 Medium; composition values describe the stock, not final-medium concentrations.
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: 8-ppt-f-2-medium, URL: https://utex.org/products/8-ppt-f-2-medium |
| 2026-03-13T06:18:52.893835Z | culturemech-id-assigner-v1.0 | Assigned CultureMech ID | Assigned stable identifier: CultureMech:000021 |
| 2026-03-17T19:45:03.865965+00:00 | normalize_media_names_to_snake_case.py | NAME_NORMALIZED | Normalized name from "8 ppt F/2 Medium" to "8_ppt_f_2_medium" for consistent matching |
| 2026-05-16T09:02:55.816580+00:00 | migrate_legacy_fields.py | MIGRATED_LEGACY_FIELDS | curation_history.date->timestamp=1; references.reference_id->reference=2; category->lowercase=1 |
| 2026-05-16T09:11:01.022502+00:00 | migrate_preparation_steps.py | MIGRATED_PREPARATION_STEPS | instruction->action+description for 9 step(s) |
| 2026-08-30T00:58:30.562272+00:00 | repair_utex_ingredients.py | REPAIRED_UTEX_COMPOSITION | Restored 7 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_f2_score35.py | RESOLVED_UTEX_F2_SCORE35 | UTEX prepares 8 ppt F/2 Medium by diluting seawater to 8 ppt and then adding the standard F/2 nutrient, trace-metal, and vitamin stocks. |
| 2026-10-10T00:39:00.252028+00:00 | codex | CURATED_UTEX_F2_INGREDIENT_AND_STOCK_STAGE_EVIDENCE | Trace-metal source mass/molarity discrepancy remains unresolved; only mass-column stock amounts are supported. The parent and 1% HTML/PDF seawater salinity versions differ; neither is silently substituted for the other. The 5% source lists vitamin doses but omits a later vitamin-addition step; no missing procedure is invented. Narrative literature variants and existing organism/growth claims are unchanged and not certified by UTEX sources. No numeric amount is invented for makeup/carrier water, seawater or the NH4MgPO4 pinch. |