Immunofluorescence tissue sections require Alexa Fluor 594 anti-mouse secondary antibody; which supplier has the fastest availability from stock?

The price of imported Alexa Fluor 594 secondary antibodies in 500 μl specifications is typically around one thousand to just over one thousand, with significant variation depending on the brand and distributor discounts; domestic or OEM products tend to be cheaper. When comparing prices, be sure to clarify whether the concentration is 0.5 mg/ml or 1 mg/ml—don't just look at the volume. For tissue sectioning, the working solution is generally diluted 1:200 to 1:500, and one vial can be used for quite a few slides, but diluted antibody is best used the same day, so don't dilute too much at once.

I recently restocked Alexa Fluor 594 donkey anti-mouse, and I usually first ask about domestic in-stock availability. Many distributors have Invitrogen/Thermo常规secondary antibodies in stock, shipping from Beijing or Shanghai in 1–3 days; some Jackson products are in stock and ship in 3–5 days; some Abcam products are available domestically, while imported transfers take 5–10 days. If it is urgent, do not place an order directly; first contact sales to confirm inventory and shipping location, and request foam box with ice packs and light protection. Lead times are greatly affected by customs clearance, so asking clearly whether it is in stock is more reliable than checking the official website.

Alexa Fluor 594 is relatively resistant to quenching, but it is still susceptible to prolonged exposure during multiplexing. In terms of imaging order, channels with longer wavelengths or weaker signals can be imaged first, and 594 should be imaged last to reduce unnecessary laser scanning; the exposure time for each channel should be kept as short as possible. Use a commercial anti-fade mounting medium for coverslipping. After staining, store the slides at 4 °C protected from light and image as soon as possible; do not wait several days before viewing. For multiplexing, single-stain controls must be included to determine whether it is bleed-through or true colocalization.

Upon receipt, first centrifuge at low temperature, then aliquot into small-volume tubes in the dark. I usually use 10–20 μl per tube, store at -20 °C in the dark, and avoid repeated freeze-thaw cycles. On the day of staining, take out a small tube and thaw at 4 °C in the dark; do not leave it at room temperature for extended periods. Keep the slide staining process covered in a humid chamber throughout, and protect from light after adding the secondary antibody. Always use an anti-fade mounting medium for coverslipping; do not wait until the sections are completely dry before mounting. Fluorescent secondary antibodies are most vulnerable to light and repeated freeze-thaw cycles, and storage conditions directly affect subsequent multiplex labeling.

When selecting secondary antibodies, besides the fluorophore, also consider species cross-adsorption. For multiplex labeling of mouse brain tissue, if other primary antibodies are from rabbit, rat, etc., it is best that the donkey anti-mouse secondary antibody is noted as pre-adsorbed against rabbit, rat, and other sera; otherwise, cross-labeling easily occurs. Alexa Fluor 594 is often paired with 488 and 647, and spectral overlap is relatively manageable. For multiplex labeling, keep the primary antibody species as separate as possible, and use highly cross-adsorbed batches of secondary antibodies. Before the experiment, run a small pilot sample first; do not directly use an entire batch of precious sections.