Immunoguided LMD approach for cell collection and analysis of Apc⁺ allele loss. (A) Guided by the nuclear accumulation of β-catenin, LMD was used to collect cells in the unseparated (I), β-catenin^IC (II) and β-catenin^CM (III) regions. IHC = immunohistochemical staining. (B) Primer set used to detect Apc⁺ and Apc^Min alleles. (C) LOH results showing loss of Apc⁺ in the β-catenin^IC region (asterisk). Lanes 1–3, ear-skin DNA from B6 Apc^Min/+ , C3H Apc^+/+ and C3B6F1 Apc^Min/+ mice; lanes 4–6, samples corresponding to I, II and III in A. Results are representative of five tumors. Scale bars, 250 μm (A).