MUHWA Glass Coplin Staining Jar — 5 Slides, Ground Glass Lid
If you do manual slide staining — H and E, Gram, Giemsa, PAS, silver — you know the drill. Fill the jar, load the slides, start the timer, check the color. This jar holds five 25x75mm slides in the upright position using molded grooves inside both long walls. Need more throughput? Pair slides back-to-back and you get 10 in one jar. The lid is ground glass, no gasket. It sits on the rim and keeps alcohol and xylene vapor where it belongs. The jar body is clear, so you can see what's happening to your sections without pulling a slide mid-protocol. 60mL total volume — fill to about 45-55mL for full immersion.
We run these daily in our own histology workflow and the main things that matter are: does the lid actually seal, do the slides stay where I put them, and can I see the staining progress without lifting the lid. This jar checks all three.
What Fits
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| Slide size | 25x75mm (1x3 inch), up to 1mm thick |
| Loading — upright | 5 slides, one per groove |
| Loading — back-to-back | 10 slides, two per groove |
| Chamber volume | 60mL total, roughly 45-55mL working |
| Material | Glass (body and lid) |
| Lid type | Ground glass joint, gasket-free |
| Autoclavable | 121 degrees Celsius, 15 psi |
| Stain compatibility | H and E, Gram, Giemsa/Wright's, PAS, GMS, Warthin-Starry, Congo red, Luxol fast blue |
| Solvent resistance | Acid alcohol, acetone, xylene — no problem |
Day-to-Day Use
H and E routine: Five slides in the jar. Hematoxylin 5-10 min depending on how fresh your stain is. Quick dip and rinse. Acid alcohol for differentiation — watch through the glass until the bluish-purple lifts to pinkish. Scott's tap water to blue. Eosin 1-3 min. Dehydrate through alcohols, clear in xylene, mount. The ground lid means you're not breathing alcohol vapor the whole time.
Gram stain on clinical isolates: Crystal violet 1 min. Iodine 1 min. This is where the clear glass matters — you're watching the decolorizer (acetone/alcohol) run, and 5 seconds too long means you've over-decolorized and your Gram-positives look Gram-negative. Drop the slides back in, safranin counterstain 30-60 sec. Done.
Giemsa for blood films: Five peripheral smears or marrow aspirates per jar. One patient panel, one jar. Wright's stain works the same way — same jar, same grooves.
PAS for kidney and liver biopsies: Periodic acid oxidation, Schiff reagent, counterstain. The glass is chemically inert to periodic acid — no surface reaction that could interfere with the aldehyde-Schiff color development. If you're running PAS on 5 serial sections from the same block, one jar handles the batch.
Silver stains (GMS, Warthin-Starry, Steiner): Silver nitrate solutions can deposit a mirror coating on reactive surfaces. This jar's glass doesn't pull silver out of solution — a real problem with some containers that depletes your stain and gives you weak results on fungal and spirochete specimens.
Teaching lab setup: Give each student a numbered jar with 2-3 unknown slides. They run the full H and E or Gram protocol independently. You can walk by and check progress through the glass without interrupting. At the end of the session, all jars go through the dishwasher on glassware cycle.
Care and Cleaning
Between stains: tap water rinse, then distilled. If crystal violet or silver residue builds up, a 30-minute soak in 10 percent nitric acid or lab glassware detergent takes it off. The ground glass joint — don't use a scrub pad on it. The mating surfaces need to stay smooth or the seal degrades. Dishwasher-safe on glassware setting. Autoclave at 121 degrees Celsius for sterility between users.
One thing to watch: if you stack jars for storage, put a piece of lab wipe between the lid of the bottom jar and the base of the top one. The ground surfaces can stick if they're perfectly clean and pressed together for weeks.
Questions We Get
Can I really fit 10 slides in this?
Yes — two per groove, back-to-back. The grooves are cut wide enough for two standard 1mm-thick slides. But at 10 slides, the spacing is tighter. If your staining protocol relies on passive diffusion alone (no agitation), consider running 5 slides for more even results, or give the jar a gentle swirl every couple of minutes with 10 loaded.
Does acid alcohol mess up the glass over time?
No. We've run these jars through hundreds of H and E cycles — the hematoxylin is acidic, the differentiator is acidic alcohol — and the glass looks the same as day one. Plastic jars get cloudy and etched; glass doesn't.
Will the lid keep xylene fumes in overnight?
The ground glass joint gives a mechanical seal that's fine for normal bench use during a staining run. It's not a gas-tight hermetic seal — if you're leaving slides in xylene overnight in a shared lab, put the jar in a fume hood or secondary container.
What if a slide breaks inside the jar?
Empty the stain, pick out the glass fragments with forceps (wear gloves), rinse thoroughly. Check the grooves for any stuck shards before reloading. The glass jar won't scratch from a broken slide, unlike plastic.
5-slide jar vs 10-slide jar — which should I buy?
If you process fewer than 30 slides a day or do specialized single-protocol work (just Gram stains, or just H and E on small batches), the 5-slide jar (this one) uses less reagent per run. If you're in a high-volume clinical histology lab doing 50 plus H and Es daily, go for the 10-slide jar — half as many jar changes. Both use the same ground glass lid design and grooved interior.
