Two opposite failures
Tissue processing must remove water and infiltrate wax in balance. Tip too far either way and the block becomes unworkable.
Over-processing
Excessive dehydration, prolonged clearing or high temperatures make tissue hard and brittle. Sections shatter, fragment or show holes. Small biopsies are especially vulnerable.
Under-processing
Residual water leaves tissue soft, wet and grey on cut surface; wax will not infiltrate, and sections compress or disintegrate.
How to prevent both
- Match the schedule to specimen size and type (delicate biopsies need gentler cycles).
- Maintain and rotate reagents on a defined schedule.
- Avoid over-thick gross sections that cannot process in the cycle time.
Why automation helps
An automatic tissue processor with reagent management runs consistent, repeatable cycles and flags reagent exhaustion — removing much of the day-to-day variability that causes both failures.