Which embedding technique involves first infiltrating tissue with celloidin?

The choice of the double embedding method is appropriate because this technique specifically involves the use of celloidin as an intermediate step prior to the final embedding process. In this method, tissues are first infiltrated with celloidin, which allows for greater preservation of delicate structures. After the initial infiltration, the tissue is typically further embedded in paraffin or another material, which provides a firmer support for the sections to be cut.

The utility of celloidin comes from its ability to penetrate deeply into tissues and provide excellent morphological detail, especially when dealing with larger specimens or those with delicate architecture. By using celloidin first, the structural integrity of the tissue is preserved, making the subsequent steps of processing and cutting easier and more effective.

The other options might involve different techniques or embedding media but do not specifically follow the sequence of using celloidin first as seen in the double embedding method. Hence, this method stands out as the correct answer regarding the use of celloidin for tissue infiltration prior to final embedding.