<p num="1"><br/><br/><br/>The present invention relates in one aspect to a method for determining the <br/>cell culture history of a cell unit labelled with more than one type of tag <br/>comprising the steps of: (a) measuring one or more parameters of each tag that <br/>is used to label the cell unit; (b) identifying each tag in the cell unit; and <br/>(c) correlating the identity of each tag to the identity of the cell unit <br/>and/or the specific cell culture conditions to which the cell unit has been <br/>exposed.<br/>
