Which precipitates at 50degC-60degC but disappears on heating -

Ans. is 'b' i.e., Light chains . Bence jones proteins coagulate at 50degC but redissolve at 70degC. . Bence Jones proteins are light chains of immunoglobulins, so may occur as the Kappa or lambda forms. . Bence jones proteins are found typically in multiple myeloma. . In multiple myeloma patients, large amount of Bence jones proteins are excreted in the urine. . Bence - jones proteins are not detected by dipstick, which detects albumin. . Light chains (B.J. proteins) are precipitated by sulfosalicylic acid.