Yes, chemicals are used during the genetic modification of organisms in the laboratory. This is because all living beings are made of chemicals; they are the building blocks from which we are all made. All foods are chemicals - table salt, pizzas, the lot!
Except for the introduced DNA (genes) and the proteins the genes produce, the actual chemicals used in the genetic modification are not present in the resultant new plant variety.
B. Lewin (2000). Genes VII. Oxford University Press
B. Alberts et. al. (2002). Molecular Biology of the Cell. Garland Science
or any other good textbook on molecular genetics.