Anti-MMP-23 Rabbit Polyclonal Antibody

Frequently Asked Questions

What molecular weight should I expect for MMP-23 on a Western blot?

MMP-23 migrates at approximately 43-45 kDa on reducing SDS-PAGE, corresponding to its 390-amino acid sequence. Because MMP-23 is a type II transmembrane protein anchored in the endoplasmic reticulum membrane, you may occasionally observe higher-molecular-weight species if the protein is incompletely denatured or forms aggregates. The antibody is raised against residues spanning the catalytic and downstream domains, so it should recognize full-length MMP-23 but not cleaved fragments lacking the epitope region. Always include a positive control lysate from cells known to express MMP-23 to confirm band identity.

Is MMP-23 secreted or intracellular, and how does this affect sample preparation?

MMP-23 is primarily intracellular, residing in the endoplasmic reticulum membrane, unlike classical matrix metalloproteinases that are secreted into the extracellular matrix. For Western blot, use whole-cell lysates prepared in RIPA or similar buffer containing detergent to solubilize membrane proteins. Conditioned medium or serum samples will yield little to no signal. If performing immunofluorescence or IHC, you should see perinuclear ER staining rather than diffuse cytoplasmic or extracellular labeling. Protease inhibitor cocktails in your lysis buffer are advisable, though MMP-23 substrate activity is not well characterized in cell lysates.

What starting dilution do you recommend for this MMP-23 antibody in Western blot?

We recommend starting at 1:1000 dilution for Western blot in 5 percent milk or BSA in TBST, which has been validated in-house with human cell lysates. Depending on MMP-23 expression level in your sample, you may need to adjust between 1:500 and 1:2000. Because MMP-23 is not ubiquitously or highly expressed in all cell types, load at least 20-30 micrograms of total protein per lane and consider enriching for membrane fractions if you encounter weak signal. Overnight incubation at 4 degrees Celsius often improves sensitivity for lower-abundance targets.

Does this antibody cross-react with mouse or rat MMP-23?

Human MMP-23 has been validated with this antibody. Mouse and rat cross-reactivity are predicted based on sequence homology in the immunogen region but have not been experimentally confirmed in our hands. Human and mouse MMP-23 share approximately 70-75 percent identity, so cross-reactivity is plausible but not guaranteed. If you are working with rodent samples, we suggest running a side-by-side comparison with a known human-positive control and verifying the band at the expected molecular weight. Peptide competition or siRNA knockdown in a rodent cell line would provide additional confidence.

What positive and negative control cell lines should I use for MMP-23?

MMP-23 expression is relatively restricted and not uniformly high across common lab cell lines. Reproductive tissues and certain epithelial cells show detectable expression, but published data on standard lysates are sparse. A practical approach is to screen a small panel of your own cell lines by Western blot or to use recombinant MMP-23 protein as a positive control if available. For a negative control, consider using lysate from cells in which MMP-23 has been knocked down by siRNA or CRISPR, or a tissue known to lack MMP-23 transcript by RNA-seq databases.

Can I use this antibody for immunohistochemistry or immunofluorescence?

Yes, Triple Point Biologics antibodies are validated for Western blot. Immunohistochemistry (IHC) and immunofluorescence (IF) validation is currently in progress. For IHC on formalin-fixed paraffin-embedded tissue, antigen retrieval with citrate buffer (pH 6.0) at high temperature is typically necessary. Because MMP-23 is an ER-resident membrane protein, expect perinuclear reticular staining rather than nuclear or secreted patterns. Start with a 1:100 to 1:200 dilution and include a no-primary-antibody control. For IF on cultured cells, fix with 4 percent paraformaldehyde, permeabilize with 0.1-0.2 percent Triton X-100, and use 1:100-1:500 dilution.

How should I store this antibody, and what is the expected shelf life?

Store the antibody at minus 20 degrees Celsius in small aliquots to avoid repeated freeze-thaw cycles, which can reduce titer and increase aggregation. The 100-microgram pack size is supplied in a glycerol- or BSA-containing buffer that remains stable for at least one year under these conditions. For daily use, keep a working aliquot at 4 degrees Celsius for up to one month. Do not store diluted antibody in blocking buffer for more than a week; prepare fresh dilutions when possible. If you observe increased background or loss of signal over time, prepare a fresh aliquot.

Why is MMP-23 sometimes called MMP-21, MMP-22, or femalysin in older literature?

Early nomenclature for MMP-23 was inconsistent. The protein was independently cloned and variously named femalysin, MIFR-1, MMP-21, and MMP-22 before the MMP-23 designation was standardized. This reflects both the unusual domain structure—lacking the classical MMP hemopexin domain—and the initially unclear relationship to other metalloproteinases. When searching the literature or cross-referencing datasets, be aware of these synonyms. The gene symbol is now MMP23B (or MMP23A in some species), and the UniProt accession O75900 provides the canonical human sequence. These historical names occasionally appear in antibody catalogs or pathway databases.