Lyophilization is a useful technique that can be used for long-term stable preservation of exosomes. Besides, lyophilized exosome can be used as control standards for FACS, WB, ELISA and other applications, as well as quantitative calibration standards for foreign and domestic exosomes in biological samples.
Immunostep Lyophilized exosome standards can be used as control standards for multiple applications, as calibration standards for biomarkers from biological samples and for immunocapture performance evaluation.
High pure exosomes improving performance over competitors
Purity validated by WB, NTA, Cytometry and functional analysis in vitro.
Tested and validated for regenerative medicine, skin, dermatological and pharma companies.
Lyophilized exosome standards easy to transport and storage and is stable for over 2 years at 2°C to 8ºC. Immunostep provides the highest quality lyophilized exosome standards isolated from a variety of biological sources, including cell culture supernatant, human plasma, serum, urine, and saliva. Exosomes are isolated by differential ultracentrifugation.
Biofluids or Cell Culture Media
Purification via ultracentrifuge
Lyophilization and Quantification
All exosome standard batches are validated using FCM, WB and NTA Analysis. Additionally, in order to compare the effects of lyophilization process we compare all lyophilized batches with respect to fresh exosomes stored at -20ºC. Dynamic range of fresh and lyophilized PC3 exosomes are analysed by flow cytometry
Figure 1: Relationship between background noise and specific signal at different exosome concentrations. Exosomes were captured by CD63+ (CloneTEA3/18) capture beads and subsequently detected by Anti-CD9PE (CloneVJ1/20).
For its validations we carry out an exosome analysis and comparative of fresh and lyophilized plasma exosomes for particle size and concentration by NTA, NanoSightLM10HSB. This analysis is carried out with 1 μl of purified exosomes diluted in 999 μL of HEPES buffer (dilution1:1000). The purified exosomes show a size distribution profiles, with peak diameters from 50 –150 nm and concentrations about 1x1010exosomes/ml. Additionally, fresh, and lyophilized MCF-7 exosome batches are analysed and compared by WB in native conditions for exosomal markers, by anti-CD9 (Clone VJ1/20) and anti-CD63 (Clon TEA3/18) antibodies at a 1:1000 dilution (0,1 mg/m).