Anti-Presenilin-1 Rabbit Polyclonal Antibody

Frequently Asked Questions

What bands should I expect on Western blot with Presenilin-1 antibody?

Presenilin-1 undergoes endoproteolytic cleavage during gamma-secretase assembly, so you will typically detect both the full-length 467-amino-acid polypeptide (approximately 50 kDa) and the N-terminal fragment (NTF, roughly 27–28 kDa) and C-terminal fragment (CTF, approximately 17–20 kDa). In most mammalian cell lysates, the NTF and CTF predominate because processing is efficient. The ratio of full-length to cleaved fragments depends on cell type and gamma-secretase assembly status. Run a positive control such as HEK293 or SH-SY5Y lysate to confirm the expected banding pattern.

What dilution should I start with for Western blot detection of Presenilin-1?

We recommend starting at 1:1000 dilution for Western blot with this rabbit polyclonal antibody. Presenilin-1 is relatively abundant in most cell types, so 1:1000 typically provides good signal with low background. If you are working with tissues or cell lines that express lower levels of PSEN1, you may titrate up to 1:500. Conversely, if background is high or signal saturates, dilute further to 1:2000. Always include a negative control lysate or PSEN1 knockdown sample to confirm specificity of your bands.

Does this Presenilin-1 antibody recognize both PSEN1 and PSEN2?

This antibody is raised against Presenilin-1 and has been validated for human PSEN1 detection. While PSEN1 and PSEN2 share roughly 67 percent amino-acid identity, antibody cross-reactivity to PSEN2 has not been validated and should not be assumed. If you need to distinguish PSEN1 from PSEN2, use isoform-specific antibodies or confirm identity by siRNA knockdown. The molecular weights of the full-length and processed fragments are similar between the two presenilins, so Western blot alone will not resolve them without specific reagents or controls.

Will this antibody work for mouse or rat Presenilin-1?

This antibody has been validated for human PSEN1. Mouse and rat PSEN1 share approximately 98 percent sequence identity with human, so cross-reactivity is predicted but not experimentally confirmed by us. If you plan to use mouse or rat samples, we recommend running a pilot Western blot alongside a human positive control to assess signal strength and specificity. Many researchers successfully use human-validated PSEN1 antibodies in rodent models, but you should verify banding patterns and consider including a species-matched knockout or knockdown control.

What sample preparation considerations are important for Presenilin-1 Western blots?

Presenilin-1 is a multi-pass transmembrane protein localized primarily to the endoplasmic reticulum and Golgi, so lysis buffers should contain detergent to solubilize membranes effectively. RIPA buffer or similar formulations work well. Avoid boiling samples at high temperature for extended periods, as this can cause aggregation of hydrophobic membrane proteins; heating at 70 degrees Celsius for 10 minutes is usually sufficient. Include protease inhibitors in your lysis buffer to prevent degradation. Because PSEN1 is cleaved during gamma-secretase assembly, heterogeneity in banding is normal and does not indicate degradation.

Can I use this antibody for immunofluorescence or immunohistochemistry of Presenilin-1?

Triple Point Biologics antibodies are validated for Western blot and immunohistochemistry applications. This rabbit polyclonal should be suitable for IHC on formalin-fixed paraffin-embedded sections; antigen retrieval is typically required for optimal staining of PSEN1. For immunofluorescence, start with a 1:100 to 1:200 dilution and optimize based on signal and background. Presenilin-1 localizes to the endoplasmic reticulum and Golgi in most cells, so expect perinuclear and reticular staining patterns. Always include a negative control such as secondary-only or isotype control to assess specificity.

How should I store the Presenilin-1 antibody and what is the expected shelf life?

Store the antibody at minus 20 degrees Celsius in single-use aliquots to avoid repeated freeze-thaw cycles, which can reduce titer and increase aggregation. For convenience during active experiments, a working aliquot can be kept at 4 degrees Celsius for up to one month with addition of 0.02 to 0.05 percent sodium azide as a preservative. Do not store in frost-free freezers, as temperature cycling degrades antibody over time. Under proper storage conditions, polyclonal antibodies typically retain activity for two to three years, though we recommend periodic positive-control checks if the vial has been stored longer than one year.

What are good positive and negative controls for Presenilin-1 Western blots?

HEK293, SH-SY5Y, and HeLa cells are reliable positive controls; all express readily detectable levels of endogenous PSEN1. For a negative control, use lysate from cells transfected with PSEN1-targeting siRNA or a PSEN1 knockout cell line if available. Brain tissue lysates are also strongly positive for Presenilin-1. Avoid using non-mammalian lysates or cells lacking the gamma-secretase complex. Including a molecular-weight ladder and a housekeeping protein such as actin or GAPDH on the same blot helps confirm transfer efficiency and loading accuracy.