GO:0035873

The directed movement of lactate across a membrane by means of some agent such as a transporter or pore. Lactate is 2-hydroxypropanoate, CH3-CHOH-COOH; L(+)-lactate is formed by anaerobic glycolysis in animal tissues, and DL-lactate is found in sour milk, molasses and certain fruit juices. [GOC:mcc, ISBN:0198506732]