A cell tissue gel, comprising one or more matrix molecules cross-linked with a cross-linking agent, and a quenching agent bound to a reactive group of the cross-linking agent, wherein the quenching agent contains a moiety that is capable of reacting with the reactive group of the cross-linking agent and the one or more matrix molecules contain one or more functional groups that are capable of cross-linking with the reactive group, the amount of the reactive group of the cross-linking agent being equal to or less than a total amount including the amount of the one or more functional groups and the amount of the moiety.