Staining Jar Rectangular

Quick Answer: A rectangular staining jar is a glass jar with a lid in which a batch of microscope slides is immersed in stain, alcohol or clearing agent at the same time. It is the batch-processing counterpart of the small round Coplin jar.

Batch Staining Compared with a Coplin Jar

This staining jar holds slides in a row along its length rather than in a small circle. Depending on the pattern, slides stand in grooves on the inner walls or sit in a separate slide rack that is lifted from one jar to the next. Either way a line of such jars forms a staining sequence, which is how routine H&E staining is organised: xylene, graded alcohols, haematoxylin, water and eosin, then back through alcohols to xylene.

Glass matters most at the clearing step. Xylene and similar solvents craze or dissolve many plastics but leave glass unaffected, so histology benches keep glass jars for dewaxing and clearing and may use a plastic rectangular jar only for aqueous stains. For a few slides at a time, the round Coplin jar uses far less stain.

Applications

• Haematoxylin and eosin staining of paraffin tissue sections in histology teaching
• Dewaxing and clearing sections in xylene or a xylene substitute
• Dehydrating slides through a graded ethanol series before mounting
• Giemsa staining of thin and thick blood films in batches
• Papanicolaou staining of cytology smears

Care & Handling

• Keep each jar in the staining line covered between runs, especially those holding alcohol or xylene, and work with good ventilation.
• Keep jars in a fixed, labelled order so solutions are never swapped.
• Drain racks or slides briefly on the rim before moving on, which reduces carry-over into the next solution.
• Filter haematoxylin regularly; surface scum and precipitate settle on slides.

Specifications

Why Choose LabEquip

Pathology and histology teaching labs usually need several matching jars to build a complete staining line, and ordering them together keeps sizes and racks consistent. LabEquip lists staining jars in its Lab Glassware range; tell us how many stations your sequence uses through the contact page.

Frequently Asked Questions

How is a rectangular staining jar different from a Coplin jar?

A Coplin jar is small and holds a handful of slides upright in grooves, which suits single stains. The rectangular jar takes a longer row of slides or a whole slide rack, so it suits batch work where many slides pass through the same sequence.

Is the jar safe to use with xylene?

Yes. Glass is not attacked by xylene, toluene or alcohols, which is why glass jars are used for clearing. Keep the lid on, work in a fume cupboard or well-ventilated room, and dispose of spent xylene as solvent waste.

How often should the solutions be changed?

It depends on how many slides pass through. Signs include weaker colour, precipitate on slides, and clearing agents turning cloudy from water carried over. Many labs filter haematoxylin daily and rotate alcohols, moving each bath one step down the line.

Can I use this jar for Gram staining?

Gram staining is normally done by flooding slides on a staining rack over a sink, because each step lasts only seconds. A jar is more useful for stains with longer immersion times, such as Giemsa or haematoxylin, and for the alcohol and xylene steps.

Why do my slides come out with stain deposits?

Deposits usually come from unfiltered stain, evaporation concentrating stain at the surface, or slides touching each other. Filter the stain, keep the jar covered, and space slides in the grooves or rack so each face is fully exposed.

How should the staining jar be cleaned?

Rinse out stain promptly, then soak in warm detergent solution and brush the grooves gently. An acid-alcohol rinse removes haematoxylin rings. Dry the jar completely before refilling it with alcohol or xylene, as leftover water makes these solutions cloudy.

Last Updated: September 2026