Improved Tissue Corrosion of Vascular Casts: A Quantitative Filtration Method Used to Compare Tissue Corrosion in Various Concentrations of Sodium and Potassium Hydroxide

In this study, we compare weights of filter retained material (11 μm particle retention) after solubilization and filtration of unfixed, un-perfused tissue (fat, liver and trachea) in sodium and potassium hydroxide (1% , 5%, 10% and 20% weight/volume, w/v) at 8, 24 and 48 hour time points at 45°C. Three detergents [1% Triton-X-100 (volume/volume, v/v), 1% 7X (v/v), 1% Terg-A-Zyme (w/v)] used in combination with hydroxide were evaluated for use in solubilizing fat. Additionally, vascular casts from mouse kidneys were corroded to test the practical effectiveness of corroding solutions on resin infused tissue. Five percent KOH for eight hours proved to be the most effective concentration and time required to corrode fatty tissue. Liver tissue was corroded most rapidly in 1% to 5% NaOH or in 1% to 20% KOH. Corrosion of trachea tissue showed that 5, 10 and 20% hydroxide (NaOH or KOH) are equally effective after 8 hours of corrosion. Use of detergents improved solubilization of fat when combined with 2% , 3% or 5% NaOH. However, fatty tissue was solubilized more rapidly without the use of detergents in 1% NaOH. Scanning electron microscopy of vascular casts shows that corrosion in 1% NaOH appears equally as effective as corrosion in 15% KOH