Novel ‘half-and-half’ design of staining jars for comparative assessment of stains

© Author(s) (or their employer(s)) 2022. No commercial reuse. See rights and permissions. Published by BMJ. INTRODUCTION At present, Coplin jars are used universally for histological staining. They are grooved glass jars which allow microscopic slides to stand separated while staining procedure. They were invented by William Coplin in 1897 and remain in use to date. Except for a few modifications such as use of plastic materials, or screwcapping to avoid evaporation or contamination, the design of Coplin jars has remained mostly unchanged. Many times, situations arise in histopathological laboratories wherein multiple special stains are to be applied on the tissue sections for histochemical confirmation of the nature of cells or material. The scenario is fairly common in researches that compare two or more histological stains. Certain study designs also revolve around comparing the effect of fixation or embedding on staining characteristics. Demonstrating suitability of histological stains in detecting microbes, pigments, or tissue elements such as muscle, cartilage, etc aids in making the diagnostic pathological procedures more accurate and efficient. In such scenarios, the extent of materials such as microscopic slides, cover slips, staining dyes and other chemicals required for the procedures correspond to the number of samples to be stained. The need may not seem significant in routine cases, but the financial toll is amplified exponentially when a large number of samples are involved in studies. Many laboratories, particularly in lowincome and middleincome countries, are not able to afford such exuberant expenditure and are ultimately unable to conduct such largescale comparative studies due to nonfeasibility. They either refrain from conducting the study or select a smaller sample size. A smaller sample size ultimately makes the finals results of their study less valid. The chemicals and materials required for research may also be difficult to procure at times. The problem is fairly common in rural areas of lowincome and middleincome countries, such as India. The problem was even further amplified in COVID19 pandemic, wherein much of the funds were focused on countering the pandemic. There was a decrease Summary box