Dihydrofolate Reductase Inhibitor Screening Kit is designed for screening DHFR inhibitors. MTX is used as a positive control. The DHFR activity is monitored by the reduction in absorbance reading at OD340 nm, while potential inhibitors arrest this decrease. The kit is adapted to a 96-well format and provides a rapid, simple, sensitive, and reliable test for high-throughput screening of DHFR inhibitors.