Statistical procedure for evaluating the sensitivity of Limulus amoebocyte lysate by using a reference lysate.

A study was designed to estimate variability of the Limulus amoebocyte lysate test by comparing a reference lysate against itself. Three technicians performed parallel tests, i.e.

Optimization of parameters in protein nitrogen unit precipitation procedure for allergenic extracts.

This work establishes the optimum conditions for the protein nitrogen unit (PNU) phosphotungstic acid (PTA) precipitation procedure for allergenic extracts. The volume of extract analyzed, the dilution of the extract prior to precipitation, the percent PTA in the precipitating solution, the washing of the precipitate, and the volume of concentrated HCl initially added to the extract were optimized, as they were found to be the factors which affected the amount of PTA precipitate obtained. Varying the digestion time, the digestion temperature, and the percent HCl in the 15% PTA precipitating solution did not cause detectable differences in the PNU values of the extracts studied.

Limulus amebocyte lysate testing of nomral serum albumin (human) in the United States since 1975.

In order to determine the reactivity of Limulus Amebocyte Lysate to albumin products, over 1500 lots of 25% Normal Serum (Human) produced by 12 U.S. licensed manufacturers were tested over the past 4 years.

Pyrogen reactions associated with the infusion of normal serum albumin (human).

In November, 1974, eight patients in three hospitals had pyrogen reactions associated with the infusion of 25% Normal Serum Albumin from the same lot. The reactions were recognized because the same physician or nurse observed several patients having recurrent reactions or because a single patient receiving several vials had consecutive reactions. The remaining albumin in three vials associated with reactions had apparent endotoxin concentrations of 4, 16, and 32 ng/ml and that 22 vials from recalled supplies had a median concentration of 4 ng/ml (range: 2 to 64) as determined by the Limulus amebocyte lysate test, but the lot again passed the rabbit pyrogen test.