Question: Can formaldehyde from alternative vendors be used for sample fixation in the Fixed RNA Profiling Assay (i.e. Single Cell Gene Expression Flex)?
Answer: We have performed limited testing to validate a few additional formaldehyde sources for sample fixation including the following:
- Sigma PN 47608: Formaldehyde solution (for molecular biology, BioReagent, ≥36.0% in H2O (T))
- Sigma PN 252549: Formaldehyde solution (ACS reagent, 37 wt. % in H2O, contains 10-15% Methanol as stabilizer (to prevent polymerization))
- Sigma PN F8775: Formaldehyde solution (for molecular biology, 36.5-38% in H2O)
If the formaldehyde validated in the 10x Demonstrated Protocols Fixation of Cells & Nuclei for Chromium Fixed RNA Profiling or Tissue Fixation & Dissociation for Chromium Fixed RNA Profiling is not available in your region, any Molecular Biology Grade stock solution of 37% formaldehyde that is ~10% methanol stabilized (with little to no precipitant) may be substituted.
We have not tested the use of alternative fixation buffers or fixation protocols with the Fixed RNA Profiling assay. For additional information, please see: Can alternative buffers or fixation protocols be used for sample fixation?
Products: Fixed RNA Profiling, Single Cell Gene Expression Flex