Methoxy-X04

Methoxy-X04 is a fluorescent dye that crosses the blood-brain barrier and selectively binds to beta-pleated sheets found in dense core amyloid Aβ plaques. Methoxy-X04 retains in vitro binding affinity for amyloid b (Ab) fibrils (K_i= 26.8 nM). Methoxy-X04 is fluorescent and stains plaques, tangles, and cerebrovascular amyloid in postmortem sections of AD brain with good specificity^[1][2]. In Vivo:Methoxy-X04 (5-10 mg/kg, i.p., once time) differentiates individual plaques in PS1/APP mice within 30 to 60 min^[2].

1. Methoxy-X04 Solution Preparation^[1]
Prepare a 5 mg/mL solution of Methoxy-X04 by dissolving Methoxy-X04 into a solution containing 10% dimethyl sulfoxide (DMSO), 45% propylene glycol, and 45% sodium phosphate buffered saline (0.9% NaCl in 100 mM phosphate buffer, pH 7.4).
2. Methoxy-X04 Solution Injection
24 hr prior to perfusion, weigh the mice and give each mouse an intraperitoneal injection of methoxy-X04 at a dose of 10 mg/kg of body weight.
3. Transcardial Perfusion of the Injected Mice
4. Brain Sectioning Using a Vibratome
5. Section Screening for the Presence of Methoxy-X04-stained Plaques
Examine each section successively, to avoid drying out the sections, using the following procedure:
Add a droplet of PBS to a microscope slide with a disposable pipette, and place the section on the droplet.
Examine the section under a fluorescent microscope (excitation 340-380 nm) to identify regions containing Methoxy-X04 labeled Aβ plaques.