BCG vaccine extensively used even in countries where efficacy against pulmonary tuberculosis is negligible. A number of possible reasons for the variable efficacy of BCG in different countries have been proposed. None have been proven, some have been disproved, and none can explain the lack of efficacy in both low-TB burden countries (US) and high-TB burden countries (India). The reasons for variable efficacy have been discussed at length in a WHO document on BCG. BCG has protective effects against some non-tuberculosis mycobacteria. BCG has been one of the most successful immunotherapies. BCG vaccine has been the "standard of care for patients with
Inoculation loop inferior but less expensive. This loop removes a consistent amount of the liquid suspended inoculum by using the phenomenon of surface tension. The inoculation loop is sterilized (even automatically) with flame (or another heat source) before and after each use. By doing this, the same tool can be reused in different experiments without fear of cross-contamination. After flame sterilization, the loop must be cooled so that the next cells the loop touches are not killed by the hot metal. Inoculation loop An inoculation loop, also called a smear loop, inoculation wand or microstreaker, is a simple tool used mainly by