FAS · Western blot design guide

FAS Western Blot Planning Guide

Plan a FAS Western blot around the catalog-observed 37.7 kDa band, image-backed PA1119 evidence, HPA controls, and verified protocol records.

Evidence assembled July 2026 · For research use; verify linked source records and product datasheet before use

Western blot protocol sheet for FAS (FAS): expected band 37.7 kDa observed, antibody PA1119, and PMC-cited SDS-PAGE protocol steps

Navigate to: Protocols Band Controls Antibodies

FAS Western Blot Experimental Design Guide

Expected bands, validated protocols, controls and antibodies — the at-a-glance facts below, then the full design guide.

Must know before running

	Expected band	37.7 kDa observed
	Observed band	37.7 kDa observed
	Gel	12-15%
	Positive control ⓘ	No defensible HPA tissue; use knockout/knockdown
	Negative control ⓘ	Use knockout/knockdown or orthogonal negative

Important caveats

Reasons your observed band may differ from the expected size.

ⓘ	Calculated mass	37.7 kDa
ⓘ	Localization	Cell membrane / Membrane raft
ⓘ	Processing / PTM	Record-dependent
ⓘ	Reactivity	Mouse / Rat / Human

Section 1

Real Curated FAS Western Blot Protocols

Start with the molecular-weight rule, then compare verified publication-derived conditions.

Recommended Western blot protocol parameters
Sample / lysate	Known-positive human lysate
Gel %	12-15%
Load	20-30 µg total protein per lane
Transfer	Semi-dry, standard transfer
Membrane	0.45 µm PVDF
Blocking	5% non-fat milk or 5% BSA in TBST
Primary	PA1119 at datasheet starting dilution
Primary incubation	Overnight at 4 °C with gentle agitation
Secondary	Species-matched HRP conjugate at validated dilution
Wash	3 × 5 min in TBST
Detection	Chemiluminescent substrate
Exposure	Bracket exposures to avoid saturation

Section 2

What Is the Expected FAS Western Blot Band Size?

Use the product-observed 37.7 kDa band as the primary planning value and retain the UniProt calculated mass as context.

What am I looking at on my blot?
37.7 kDa	Matches the authoritative product WB observation.
37.7 kDa calculated	Use as UniProt context, not as a replacement observed band.
Unexpected additional signal	Do not assign identity without orthogonal positive/negative controls.

💡Expected FAS appearancePlan around 37.7 kDa and keep the calculated mass as supporting context.

How each factor affects band size
Catalog-observed band	37.7 kDa; use this as the primary experimental expectation.
Calculated mass	37.7 kDa from UniProt P25445; retain as context.
Gel selection	12-15%; shared with the recommended protocol and poster.
Specificity check	Compare the lead HPA positive and negative controls with PA1119.

Why is my band missing or off?
Situation	Likely cause	Next action
37.7 kDa	Matches the authoritative product WB observation.	Confirm with orthogonal controls and the linked product record.
Additional band	May reflect processing, modification, or non-specific signal.	Run a dilution series and compare positive/negative controls.
Weak signal	Target abundance or transfer may be limiting.	Verify transfer, increase positive-control abundance, and bracket exposure.

Sources: UniProt P25445 Human Protein Atlas product datasheet (PA1119)

Experiment evidence

Western blot images showing FAS band

PA1119 · FAS — observed 37.7 kDa WB validation

PA1119 · FASObserved 37.7 kDa · product-specific WB image

← swipe / scroll for more images →

Real WB data behind the band-size expectations in this section.

Sample controls for FAS Western blot

🧪No defensible HPA positive control was available; do not invent one.

HPA protein score determines control status; other expression data is supporting context only.

HPA tissue expression evidence for FAS

Comprehensive Human Protein Atlas IHC scoring per tissue. Rows are taken directly from the HPA tissue chart on each tissue page — click any row's HPA link to view the source.

Positive expression · recommended positive controls

Tissue	Cell type	Level	Evidence	Source

Undetected expression · recommended negative controls

The Human Protein Atlas exposes no structured IHC tissue profile for FAS, so tissue-level positive/negative controls cannot be listed here. Use a documented FAS-positive lysate (recombinant FAS or a known-expressing line) as the positive control and a FAS knockdown/knockout lysate as the negative control; confirm against the antibody datasheet.

Tissue	Cell type	Level	Evidence	Source

Section 3

Advanced FAS Western Blot Tips

Deeper troubleshooting and optimisation questions for FAS, answered from its protein features.

Which band should guide the blot?

Use 37.7 kDa, the observation attached to the authoritative PA1119 WB record.

How should calculated mass be interpreted?

Treat the UniProt calculated mass as context; it does not replace the catalog-observed 37.7 kDa expectation.

Which positive control should I start with?

No defensible positive tissue was supplied; do not invent one.

Which negative control is defensible?

Use a target knockdown/knockout control when no HPA Not detected tissue is available.

Which gel should I use?

Use 12-15% consistently across the quick facts, protocol table, and poster.

What transfer method to use for FAS Western blot?

Use the transfer method in the recommended protocol and verify transfer before blocking.

How should PA1119 be started?

Start at the linked datasheet condition and run a three-point primary-antibody dilution test.

Which publication-derived protocols can I compare?

No verified publication protocol was supplied; use only the deterministic recommended protocol.

Boster reagents

FAS Western Blot Reagents

Mouse/Rat/Human-reactive FAS Western blot reagents with authoritative product imagery.

Real WB data Western blot validation image for FAS using PA1119; observed band 37.7 kDa

Anti-Fas Antibody Picoband®

Cat # PA1119

View product →

Real WB data Western blot validation image for FAS using PB9252; observed band 37.7 kDa