COMING BY TRAIN FROM PARIS
From anywhere in Paris take the appropriate metro lines to reach the RER B and then take the direction St Rémy-lès-Chevreuse.
Solution 1: get out at Massy Palaiseau, and take the bus 91.06 (B or C) or 91.10 till the "Orme des Merisiers" stop (20 minutes ride, very frequent buses in the morning and in the evening). Map of bus stops at Massy-Palaiseau here. Timetables here.
Solution 2: get out at Le Guichet, and take the bus 9 to "Orme des Merisiers" (10 minutes ride, interval between buses 10 to 20 minutes). Timetables here.
From the bus stop "Orme des merisiers, walk to the lab following this map.
Solution 3: get out at Le Guichet, then phone +33 1 69 08 55 29 so that we get there and pick you up at the station by car.
Solution 4: get out at Gif-sur-Yvette and walk up through the forest (20 minutes walk, we can explain the way if you come often!)
For all your travels in Paris and its surrounding region, see the timetables and routes given by RATP.