Fluorescent, Non-Radioactive Assays to Quantify Amino Acid & Cystine Uptake in Live Cells for Oncology, Immunometabolism and Drug Discovery
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If you’re exploring how tumour and immune cells rewire nutrient uptake and need readouts that are fast, safe, and screening-ready, these plate-based fluorescent kits let you quantify transporter activity in live cells in under an hour. They replace radioisotopes and LC/MS-heavy workflows with a simple assay format you can run on a plate reader (and adapt to imaging or flow cytometry) to support transporter inhibition, immunometabolism studies, and ferroptosis research. |
Why Researchers Choose These Assays
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Fast, fluorescent readout (no radioactivity): quantify uptake in under 1 hour.
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Works with your existing platforms: compatible with plate readers, imaging, or flow cytometry workflows.
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Made for mechanism and screening: ideal for transporter inhibition, ferroptosis, and oxidative stress studies.
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Relevant biology: supports research in cancer metabolism, immunometabolism, and immunotherapy.
UP04 – Amino Acid Uptake Assay Kit
Fluorescent, non-radioactive neutral amino acid uptake via LAT transporters
UP05 – Cystine Uptake Assay Kit
Fluorescent, non-radioactive readout of xCT (SLC7A11) transporter activity
After amino acid analogues (BPA) are taken up into cells via amino acid transporters, the fluorescent probe permeates the cell membrane and binds to the amino acid analogues, emitting fluorescence.
The cystine analogue (CA) in this kit can be taken up into cells via xCT, and the incorporated CA can be specifically detected using the Fluorescent Probe and Reducing Agent. Thus, xCT activity can be measured easily.
- Measures neutral amino acid uptake via LAT transporters
- Fluorescent amino acid analogue → quantified in < 1 hour
- Measures xCT transporter activity
- Key for ferroptosis research
- Non-radioactive alternative to traditional assays
- Cancer metabolism
- LAT1 inhibitor screening
- Immunometabolism
- Nutrient uptake studies
- Ferroptosis studies
- Oxidative stress research
- Redox metabolism
- Drug screening (xCT inhibitors)
Amino acids are essential for intracellular protein and nucleic acid synthesis, especially for cancer cells which are proliferating continually. Since the supply of acetyl-CoA from the glycolytic pathway is decreased in cancer cells, they have a further increased demand for amino acids, an important nutrient source for the TCA cycle. Research has shown that cancer cells increase expression of the amino acid transporter LAT1 (L-type amino acid transporter 1) and take up large numbers of amino acids, making LAT1 a promising target for anti-cancer drug discovery.
In immunotherapy, not only metabolic changes in cancer cells but also in immune cells are considered to affect treatment. For example, as senescence occurs in immune cells, their metabolism changes and their immune capacity to attack cancer cells decreases. Therefore, research is ongoing on nutrient uptake regulation by immune cells to improve the effectiveness of cancer immunotherapy.
The cystine transporter xCT is a crucial transporter that maintains cellular redox balance by regulating glutathione synthesis via cystine uptake. xCT is highly expressed in several types of cancer cells and is expected to be a therapeutic target for cancer. Therefore, xCT has recently attracted researchers’ attention as one of the targets for cancer treatment.
The xCT inhibitors sulfasalazine and erastin are known to reduce intracellular glutathione levels by inhibiting cystine uptake, thereby inducing ferroptosis, a form of cell death. It is also known that immune cells highly express xCT upon activation, suggesting that intracellular redox regulation via cystine uptake is also important for immune responses.
UP04 – Amino Acid Uptake Assay Kit Data Example
Evaluation of BCH (LAT inhibitor)
BCH (2-Aminobicyclo[2.2.1]heptane-2-carboxylic acid) inhibits BPA uptake in HeLa cells, supporting LAT-linked transport measurement.
Cell Line: HeLa cells
Medium: MEM （5.5 mmol/l Glucose）
Incubation: 1 mmol/l BCH/HBSS (Hanks' Balanced Salt Solution), 37℃, 30 min
Instrument：Fluorescent Microscopy(Ex=340-380 nm, Em: 435-485 nm)
Instrument： Plate Reader (Ex=360 nm, Em: 460 nm)
Instrument: Flow Cytometer (Ex=405 nm, Em: 425-475 nm)
Evaluation with BCAA (L-Leucine)
Adding L-Leucine and BCH inhibits BPA uptake, consistent with competition/inhibition of LAT-mediated transport.
Cells: HeLa
Inhibitors: LAT1 inhibitor BCH (2-Aminobicyclo[2.2.1]heptane-2-carboxylic acid) and L-Leucine
UP05 - Cystine Uptake Assay Kit Data Examples
Evaluation of xCT inhibitors (sulfasalazine or erastin)
In HeLa cells, fluorescence intensity decreases significantly in sulfasalazine and erastin conditions, consistent with inhibition of cystine uptake.
Comparison with radioisotope method
Uptake trends measured using this kit correlate with [14C]-labelled cystine assays across WT, xCT-KO and xCT-OE cells (decreased in KO, increased in OE vs WT).
*Data kindly provided by Professor Hideyo Sato and Assistant Professor Mami Sato, Niigata University.
Why Researchers Should Switch to These Uptake Kits
UP04 – Amino Acid Uptake Assay Kit (LAT transporters)
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Transporter-relevant design: proprietary amino acid analogue (BPA) transported via LAT1, LAT2, and ATB.
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Rapid, simple plate-based workflow: no radioactivity, no LC/MS, ideal for screening and iterative inhibitor work.
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LAT-linked fluorescent uptake assay: fully fluorescence-based, non-radioactive detection.
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Direct visualisation of uptake in live cells, supporting both quantification and imaging confirmation.
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Built for LAT1-focused oncology and immunotherapy metabolism research, where LAT1 dependence is a key biological question.
UP05 – Cystine Uptake Assay Kit (xCT / SLC7A11)
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High xCT specificity: uses selenocystine as the cystine analogue (CA), enabling highly specific transport through xCT (SLC7A11).
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Rapid, simple plate-based workflow: no radioactivity, no LC/MS, meaning easier adoption and fewer workflow bottlenecks.
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Highly specific readout of xCT activity: designed for ferroptosis and redox biology programmes where interpretation matters.
Q&A Section
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What kind of microplate can be used for this kit?
Company Product Name Cat No. ibidi μPlate 96 well ibiTreat black S 15 ib89626 AGC techno glass EZVIEW Glass Bottom Culture Plate LB 96well 5866-096 Thermo Fisher 96 Well Black/Clear Bottom Plate, TC Surface, Pack of 10 165305 -
Which cell lines have been tested by Cystine Uptake Assay Kit (UP05)?
A172, A549, A375, HCT116, HepG2, HL60, HT1080, MEF, SBC-5, U-251 MG cell lines.
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Which cell lines have been tested by Amino Acid Uptake Assay Kit (UP04)?
Adherent Cells include Hela, A549, HepG2, MCF-7, C2C12, MEF, U251 and Floating Cels include MOLT4.
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Can the cystine uptake solution be stored?
CA uptake solution cannot be stored. Prepare the required amount of CA uptake solution at the time of use.
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Is it possible to store the BPA solution and working solution for a period of time?
BPA solution and working solution cannot be stored.
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Are there any buffers other than cystine-free medium that can be used for the preparation of CA Uptake solution?
We have used HBSS or PBS with 0.1% Glucose to prepare CA uptake solution when testing HeLa cells.
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Is it possible to fix cells after incorporating BPA into living cells?
Cells cannot be fixed after staining because the probe leaks out of the cells.
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Reference
Article content created by Tebubio using courtesy materials provided by Dojindo Europe.
Need Expert Guidance for Your Amino Acid Uptake & Ferroptosis Research?
Our assay specialists can help you choose the most suitable uptake tools, UP04 for LAT-linked neutral amino acid transport and/or UP05 for xCT-mediated cystine uptake, along with complementary application support for oncology, immunometabolism and drug discovery.
Get tailored guidance to optimise experimental design, select the right controls and inhibitors, strengthen transporter- and pathway-level interpretation, ensure reproducibility, and accelerate robust, publication-ready results.