StemSpan?-AOF
Animal Origin-Free cGMP HSC Expansion Medium

Hematopoietic stem cells (HSCs) are widely being used in cell and gene therapy applications. When transferred into patients, these cells act as "living drugs" and have the ability to treat systemic diseases. When producing HSCs for cell therapy, it is important to minimize risk and variability in your cell culture media to ensure consistent, reproducible performance and safety.
Whether you are performing fundamental research or ready to transition to the clinic, the new StemSpan?-AOF medium helps minimize the risk of viral contamination in your cell therapy research. Choosing animal origin-free (AOF) cell culture conditions can facilitate a smoother pathway to the clinic by helping you avoid regulatory roadblocks.
StemSpan?-AOF is also manufactured under relevant cGMPs, ensuring the highest quality and consistency for reproducible results. To learn more about our approach to quality and compliance, including GMP, explore the resources on our Quality page. There, you’ll also find information on the regulatory support we can provide to help you move your research from the bench to the clinic.
On this page you will find tools and resources that support your path to the clinic, our answers to some frequently asked questions, and a form where you can sign up to try StemSpan?-AOF medium.
Why Use StemSpan?-AOF for Cell Therapy Research?
- Minimize the risk of viral contamination by using media that does not contain any animal-derived raw materials to at least the secondary level of manufacturing.
- Ensure consistency in your experiments by using serum-free and animal-origin free culture conditions.
- Customize your cell-culture conditions by adding StemSpan? Expansion Supplements, individual cytokines or additives to suit your specific cell therapy research needs.
See the Data
Enhance your cell therapy research by choosing the only truly animal-origin free medium on the market for the expansion of hematopoietic cells. Compared to the currently available xeno-free alternatives, StemSpan?-AOF consistently supports equal or greater levels of expansion of CD34? cells while providing more defined conditions.

Figure 1. StemSpan?-AOF Supports Equivalent or Greater Expansion of Human CD34+ and CD34brightCells than Other Commercial Media
Purified cord blood (CB)-derived CD34? cells were cultured for 7 days in StemSpan?-AOF (orange bar), and in four xeno-free media formulations from other suppliers (Xeno-Free Commercial Alternative, grey bars), including (in random order) SCGM (Cellgenix), X-VIVO? 15 (Lonza), Stemline? II (Sigma), and StemPro?-34 (Thermo). The (A) frequency and (B) cell expansion of viable CD34+ and CD34bright cells in culture were based on viable cell counts and flow cytometry results. StemSpan?-AOF, the only animal origin-free formulation, showed equivalent performance to all xeno-free alternative media tested. All media were supplemented with StemSpan? CD34? Expansion Supplement and UM171*. Data shown are mean ± SEM (n = 8). See All Product Data >
Note: Data shown for StemSpan?-AOF were generated with the original phenol red-containing version, StemSpan?-ACF (Catalog #09855). Internal testing shows that the performance of the new phenol red-free, cGMP-manufactured version, StemSpan?-AOF (Catalog #100-0130), is comparable.
*Similar results are expected when using UM729 (Catalog #72332) prepared to a final concentration of 1 μM. For more information including data comparing UM171 and UM729, see Fares et al., 2014.
Try StemSpan?-AOF in the Lab
Are you interested to see how your cultures perform in StemSpan?-AOF? Sign up below to have our product specialist contact you about an introductory offer to try the StemSpan?-AOF medium in your lab.
Watch the ISSCR Innovation Showcase Video
Learn more about how you can use StemSpan?-AOF to effectively gene edit cord blood-derived CD34? cells with this presentation from Amanda Fentiman, Senior Product Manager, Hematology at ISSCR 2021.
Case Study: See How StemSpan?-AOF Performs in Gene Editing Applications
Using media that supports CRISPR-Cas9 gene editing of hematopoietic cells can help take your cell therapy research to the next level. Read this case study to learn more about how StemSpan?‑AOF can provide robust and optimal culture conditions for HSPC expansion in gene-editing applications.
Genome Editing of Human CD34+ HSPCs
In this technical bulletin on genome editing, read the case study showing the use of StemSpan?-AOF as a reliable and effective medium for genome editing of CD34? HSPCs.
Frequently Asked Questions
What does animal origin-free mean and why is it important?
StemSpan?-AOF is a specialized animal origin-free medium with traceability to the secondary level of manufacturing. This means that it is not manufactured using any raw material ingredients derived from an animal (including human) tissue, cell, or body fluid and that the components used to manufacture the raw materials are also not derived from an animal tissue, cell, or body fluid. This is important because it means that StemSpan?-AOF is viral-safe by design, easing the path to clinical applications with straightforward traceability documentation that can be provided to regulators.
How is StemSpan?-AOF different from other media for CD34? cell culture?
- Entirely animal origin-free with traceability to the secondary level
- Available data to support the maintenance of primitive CD34brightCD90+CD45RA- cells in culture for 7 days
- Compatible with CD34? cell expansion, differentiation, and gene editing applications
Do I need to supplement StemSpan?-AOF with anything extra?
StemSpan?-AOF is a highly enriched basal medium; the only things to add are your desired cytokines and growth factors needed to stimulate your cells of interest. StemSpan?-AOF is supplied in a single 500 mL format and does not require the addition of serum or purified serum derivatives.
Is there a Drug Master File (DMF) for StemSpan?-AOF that I can reference?
Yes, we have received a letter of acknowledgement from the FDA of our Master File. To receive a Letter of Authorization (LOA) to reference the MF for StemSpan?-AOF, please fill out our LOA request form.
Other Products That Support Your Cell Therapy Research
If you would like to try our other high-compliance reagents or cell culture media, like TeSR?-AOF for hPSCs, you can request an introductory offer by submitting a form here.