A comparative study to evaluate liquid dish washing soap as an alternative to xylene and alcohol in deparaffinization and hematoxylin and eosin staining

Clearing Properties Between Coconut Oil and Xylene in Histological Tissue Processing

Xylene is the commonest clearing agent even though it is hazardous and costly. This study evaluated the clearing properties of coconut oil as an alternative cost-effective clearing agent for histological processes. Ten (10) prostate samples fixed in formalin were taken and each one was cut into 4 before randomly separating them into four groups (A, B, C and D). Tissues were subjected to ascending grades of alcohol for dehydration. Group A was cleared in xylene and Groups B, C, and D were cleared at varying times of 1hr 30mins, 3hrs, and 4hrs in coconut oil respectively before embedding, sectioning, and staining were carried out. Gross and histological features were compared. Results indicated a significant shrinkage in coconut oil-treated specimen compared with the xylene-treated specimen and only the tissues cleared in coconut oil for 4hrs were as rigid as the tissues cleared in xylene (p > 0.05). No significant difference was found in either of the sections when checked for cellular details and staining quality (p > 0.999). Coconut oil is an efficient substitute for xylene in prostate tissues with a minimum clearing time of 4hrs, as it is environmentally friendly and less expensive, but causes significant shrinkage to prostate tissue.

Effectiveness of neutral honey as a tissue fixative in histopathology

Background: In routine histopathology, 10% neutral buffered formalin (NBF) is the choice fixative. However, formalin is a human carcinogen, so there is a necessity for a safer alternative. To the best of our knowledge, neutral honey, not natural or artificial honey, has not been tested to fix histological samples. This study determined the effectiveness of neutral buffered honey and other types of fixatives to fix histological tissues. Methods: The study was conducted between July 2019 and August 2020 at Sultan Qaboos University, Oman. Sections from three rat livers, kidneys, and stomach tissues were fixed with 10% NBF, neutral buffered Sumer honey, neutral buffered date honey, formalin, Sumer honey, date honey, alcoholic formalin, alcoholic Sumer honey, and alcoholic date honey for 24 hours. Samples were stained with hematoxylin and eosin (H&E), special stains, and vimentin methods. Three expert biomedical scientists then evaluated the fixed and stained samples for the quality of all sections. The fixation ability of the different honey solutions was then compared to 10% NBF and the utility was determined using nuclear and cytoplasmic criteria, specificity, and intensity. Results: H&E showed adequate staining in all groups compared to 10% NBF. The specificity and intensity of all groups for the Periodic acid-Schiff method were identical to 10% NBF except for Sumer honey and alcoholic date honey. Vimentin showed comparable findings with 10% NBF as there were no significant differences. Conclusions: The findings of this study encourage the use of honey, including neutral, as a possible safe substitute fixative for formalin, however, further experiments on larger specimens should be conducted.

A substitute to xylene in deparaffinization and clearing prior to coverslipping in histopathology

INTRODUCTION:

Deparaffinization and clearing prior to coverslipping are important steps in all staining methods in histopathology. Xylene is the most commonly used agent worldwide. However, xylene is toxic. We evaluated safer alternative dewaxing and clearing agents prior to coverslipping in a histopathology laboratory.

MATERIALS AND METHODS:

Thirteen different fresh surgical tissues were cut into two halves. One half processed using xylene and the other half processed using UltraClear™. Five groups were designed. For each Group of A, B, C, and D, 100 slides were cut from xylene-processed blocks. For Group E, 100 slides were cut from UltraClear™-processed blocks. Group A is the standard method. Group B evaluates UltraClear™ as a dewaxing agent only. Group C evaluates UltraClear™ as a clearing agent prior to coverslipping only. Group D evaluates UltraClear™ as both dewaxing and clearing agents prior to coverslipping. Group E evaluates UltraClear™ as both dewaxing and clearing agents prior to coverslipping. Six parameters were evaluated: nuclear staining, cytoplasmic staining, cell morphology, clarity of staining, uniformity of staining, and cost.

RESULTS:

Groups B, C, and D showed 79% (P = 0.054), 83% (P = 0.221), and 80% (P = 0.079) adequacy when compared with Group A (89%), respectively. However, Group E showed only 76% (P = 0.016) adequacy. UltraClear™ is more expensive than xylene.

CONCLUSION:

UltraClear™ is a promising dewaxing agent. It is also a good clearing agent for use prior to coverslipping in histopathology laboratory. Cost-benefit balance between safety of laboratory workers, good quality staining, and cost-effective strategy needs to be further studied.

Alternative to xylene as a clearing agent in histopathology

INTRODUCTION:

Clearing is an essential step in processing tissue for light microscopy. Xylene is the clearing agent used most commonly worldwide. Xylene is toxic and therefore a threat to personnel working in histopathology laboratories. We evaluated a safer alternative clearing agent for use in the histopathology laboratory.

MATERIALS AND METHODS:

We used 230 formalin-fixed, paraffin-embedded tissue blocks from 19 different tissues. Half of the specimens were processed using xylene and half were processed using UltraClear™. Tissues were evaluated for eight parameters: sectioning, nuclear staining, cytoplasmic staining, overall cell morphology, clarity of staining, uniformity of staining, quality of immunohistochemistry (IHC), and cost.

RESULTS:

Both UltraClear™ and xylene processed sections scored 100% for IHC. Sections processed using UltraClear™ were easy to cut (81.7%) as were xylene processed sections (96.5%). UltraClear™ processed sections showed 67%, 60.9%, 52.2%, 63.5%, and 67% for nuclear staining, cytoplasmic staining, cell morphology, clarity of staining, and uniformity of staining, respectively. UltraClear™ is twice as expensive as xylene. We found that tissues processed using UltraClear™ were easy to cut and worked well for both hematoxylin and eosin and IHC staining.

CONCLUSION:

UltraClear™ is less toxic, less flammable, friendlier to the environment, and easy to handle, but it is two times expensive than xylene. The findings of this study recommend the use of UltraClear™ solution as a routine clearing agent in histopathology laboratories. However, further studies are required.