In which specimen were cells first identified

The appropriate response is a cork. The cell was first seeked  and named by Robert Hooke in 1665. He said that it looked very similar to cells or little rooms which friars occupied. So in this way that is how he determining the name. However what Hooke really observed was the dead cell dividers of plant cells AKA (cork) as it showed up under the magnifying lens.

Explanation:

this protocol provides a detailed procedure for co-immunoprecipitation (co-ip) to identify protein–protein interactions.