A few common errors in the use of conjunctions are shown in the following table:

avoid	xxxx	better
"we thank to"		"we thank"
"in the same time"		"at the same time"
"the Rb1 gene was mapped on chromosome 15"		"the Rb1 gene was mapped to chromosome 15" or: "the Rb1 gene is on chromosome 15"
"PBMCs of patients"		"PMBCs from patients"
"10 nM of Du86"		"10 nM Du86"
"antiserum against to PL-1"		"antiserum against PL-1" or: "antiserum to PL-1"