We have prepared two types of cDNAs encoding mouse immunoglobulin heavy (VH) and light (VL) chain variable (V) domains against UV-induced DNA damage by the polymerase chain reaction (PCR). The amplified cDNA was cloned for sequencing and expression, and the nucleotide sequences of the V domains were determined. The deduced amino acid sequences of the complementarity-determining regions (CDRs) indicated that CDR3 of the VH domain and CDR2 of the VL domain might be concerned with the recognition of photolesions.