In the quest for a cure for Parkinson’s disease, scientists have travelledmany avenues. One is the use of cells from aborted fetuses. These cellshave been proven to restore the lacking dopamine production in thebrain of the afflicted person. In order to place the cells inside the patient’sbrain, a so-called cell suspension must be made and administered, whichis a liquid produced in a laboratory containing mainly foetal brain cells.This can be transplanted either into rats for research or into human subjectsfor clinical trials, and theoretically for treatment.For people encountering the cell suspension, it enters their lives indifferent ways, giving it diverse shape and meaning; it also gives rise tomany different kinds of expectations. Thus, a delicate issue such as theuse of the cell suspension, with its foetal origin, provides a good basisfor discussing what I would call ‘science’s understanding of/engagementwith knowledge’. Normally when issues of participation in scienceare discussed, it is done in relation to how stakeholders and otherwiseaffected people such as for example patients and relatives understand science.The so-called ‘information deficit model’, where the public wasseen as lacking in knowledge and understanding, was a concept commonin the research field of the ‘public understanding of science’ (Evans &Durant 1995; Sturgis & Allum 2004). This model was gradually replacedby views in which engagement and information exchange were regardedas more of a two-way communication between researchers and the public;lay-people’s understanding was also seen as a kind of knowledge. Thedevelopment of a more reciprocal view of knowledge is expressed in thenewer concept of ‘public engagement with science and technology’ (see e.g. Stilgoe, Lock & Wilsdon 2014). Still, even with the newer terminologyand the ideas connected with it, much of the focus is on the ‘recipients’of scientific results, and less on those who produce them. This isproblematic, because it sets the researchers’ views apart as somethinglargely free from values, meaning and desire, as opposed to the afflictedlay-peoples’ views. In this chapter, I will give a more nuanced and complexpicture of how scientists value what they do. With the help ofinterviews with two laboratory researchers, I focus upon how they understand,value and provide meaning to the foetal cell suspension that theywork with. I argue that they do it differently, depending on how theyinteract with the suspension. The aim is to gain a better understanding ofhow the scientific knowledge comes into being in a scientific laboratory.The analysis thus problematizes how participation can be understood ina laboratory context.