Heat-treated limulus amebocyte lysates

1. A method of preparing a Limulus amebocyte lysate with increased specificity for (1→3)-β-D-glucan, the method comprising the step of heating the Limulus amebocyte lysate to a temperature above 40° C. to reduce sensitivity to an endotoxin, with the proviso that the lysate is not heated to 56° C. for 30 minutes.

2. A method of preparing a Limulus amebocyte lysate having reduced sensitivity to an endotoxin, the method comprising the step of heating the Limulus amebocyte lysate to reduce Factor C activity in the lysate while retaining sensitivity to (1→3)-β-D-glucan.

3. The method of claim 1 , wherein the Limulus amebocyte lysate retains sensitivity to 100 ng/mL carboxymethylated pachyman.

4. The method of claim 3 , wherein the Limulus amebocyte lysate retains sensitivity to 1 ng/mL carboxymethylated pachyman.

5. The method of claim 4 , wherein the Limulus amebocyte lysate retains sensitivity to 1 pg/mL carboxymethylated pachyman.

6. The method of claim 5 , wherein the Limulus amebocyte lysate retains sensitivity to 0.1 pg/mL carboxymethylated pachyman.

7. The method of claim 1 , wherein the resulting Limulus amebocyte lysate is a (1→3)-β-D-glucan-specific lysate.

8. The method of claim 1 , wherein (1→3)-β-D-glucan sensitivity is not reduced by a factor of more than 10.

9. The method of claim 1 , wherein the endotoxin sensitivity is reduced by a factor of at least 100.

10. The method of claim 1 , wherein the endotoxin sensitivity is reduced by a factor of at least 1,000.

11. The method of claim 1 , wherein the endotoxin sensitivity is reduced by a factor of at least 10 6 .

12. The method of claim 1 , wherein the Limulus amebocyte lysate is heated to between 40° C. and 80° C.

13. The method of claim 1 , wherein

(i) if the temperature is no more than 45° C., the heating time exceeds 40 minutes; and

(ii) if the temperature is more than 55° C., the heating time is less than one minute.

14. The method of claim 13 , wherein the temperature is no more than 45° C.

15. The method of claim 13 , wherein the temperature is more than 45° C. and less than 55° C.

16. The method of claim 15 , wherein the temperature is more than 45° C. and less than 52° C.

17. The method of claim 16 , wherein the temperature is more than 45° C. and less than 50° C.

18. The method of claim 1 , wherein the heating time exceeds t A1 hours, where t A1 =0.825*2.718 (56340/(T+273)) /(9.54*10 76 ), where T is the temperature in ° C.

19. The method of claim 18 , wherein the heating time exceeds t A2 hours, where t A2 =1.65*2.718 (56340/(T+273)) /(9.54*10 76 ), where T is the temperature in ° C.

20. The method of claim 1 , wherein the heating time is no more than t B1 hours, where t B1 =0.353*2.718 (76510/(T+273)) /(2.20*10 103 ), where T is the temperature in ° C.

21. The method of claim 1 , wherein the Limulus amebocyte lysate is heated for at least five minutes.

22. The method of claim 21 , wherein the Limulus amebocyte lysate is heated for at least twenty minutes.

23. The method of claim 1 , wherein the Limulus amebocyte lysate is heated for no more than two hours.

24. The method of claim 1 , comprising the additional step of removing a precipitate from the Limulus amebocyte lysate after the step of heating the lysate.

25. The method of claim 1 , further comprising lyophilizing the Limulus amebocyte lysate after the step of heating the lysate.

26. The method of claim 2 , wherein the Limulus amebocyte lysate retains sensitivity to 100 ng/mL carboxymethylated pachyman.

27. The method of claim 26 , wherein the Limulus amebocyte lysate retains sensitivity to 1 ng/mL carboxymethylated pachyman.

28. The method of claim 27 , wherein the Limulus amebocyte lysate retains sensitivity to 1 pg/mL carboxymethylated pachyman.

29. The method of claim 28 , wherein the Limulus amebocyte lysate retains sensitivity to 0.1 pg/mL carboxymethylated pachyman.

30. The method of claim 2 , wherein the resulting Limulus amebocyte lysate is a (1→3)-β-D-glucan-specific lysate.

31. The method of claim 2 , wherein (1→3)-β-D-glucan sensitivity is not reduced by a factor of more than 10.

32. The method of claim 2 , wherein the endotoxin sensitivity is reduced by a factor of at least 100.

33. The method of claim 2 , wherein the endotoxin sensitivity is reduced by a factor of at least 1,000.

34. The method of claim 2 , wherein the endotoxin sensitivity is reduced by a factor of at least 10 6 .

35. The method of claim 2 , wherein the Limulus amebocyte lysate is heated to between 40° C. and 80° C.

36. The method of claim 2 , wherein

(i) if the temperature is no more than 45° C., the heating time exceeds 40 minutes; and

(ii) if the temperature is more than 55° C., the heating time is less than one minute.

37. The method of claim 36 , wherein the temperature is no more than 45° C.

38. The method of claim 36 , wherein the temperature is more than 45° C. and less than 55° C.

39. The method of claim 38 , wherein the temperature is more than 45° C. and less than 52° C.

40. The method of claim 39 , wherein the temperature is more than 45° C. and less than 50° C.

41. The method of claim 2 , wherein the heating time exceeds t A1 hours, where t A1 =0.825*2.718 (56340/(T+273)) /(9.54*10 76 ), where T is the temperature in ° C.

42. The method of claim 41 , wherein the heating time exceeds t A2 hours, where t A2 =1.65*2.718 (56340/(T+273)) /(9.54*10 76 ), where T is the temperature in ° C.

43. The method of claim 2 , wherein the heating time is no more than t B1 hours, where t B1 =0.353*2.718 (76510/(T+273 )) /(2.20*10 103 ), where T is the temperature in ° C.

44. The method of claim 2 , wherein the Limulus amebocyte lysate is heated for at least five minutes.

45. The method of claim 44 , wherein the Limulus amebocyte lysate is heated for at least twenty minutes.

46. The method of claim 2 , wherein the Limulus amebocyte lysate is heated for no more than two hours.

47. The method of claim 2 , comprising the additional step of removing a precipitate from the Limulus amebocyte lysate after the step of heating the lysate.

48. The method of claim 2 , further comprising lyophilizing the Limulus amebocyte lysate after the step of heating the lysate.