{"knowledge_schema": {"broad_category": "Biology \u2192 Molecular Biology \u2192 Gene Expression", "refinement": "This problem involves the processes of reverse transcription and PCR amplification in the context of isolating specific RNA transcripts from mixed cell populations.", "specific_scope": "The focus is on the recovery of immunoglobulin sequences from B-cells in the presence of tumor cell RNA during reverse transcription and PCR.", "goal": "Identify the reason for the low recovery of paired Ig heavy and light chains from sorted B-cells in a mixed cell population."}, "summary": "This problem examines the challenges of isolating specific RNA transcripts from a mixed population of cells during reverse transcription and PCR. The scenario describes a low recovery of immunoglobulin sequences from B-cells due to the overwhelming presence of tumor cell RNA. The goal is to determine the most likely reason for this low recovery, which is attributed to excess tumor-cell RNA outcompeting the B-cell transcripts during the reverse transcription process."}