The protein pad of the reagent strip is designed to react mainly with albumin, so it misses free light chains. Sulfosalicylic acid precipitates protein in general and therefore detects light chains as well. The question tests the difference in principle between the two methods.
학습 참고용입니다. 실제 임상은 최신 지침과 소속 기관 프로토콜을 따르세요.