差那么点应该可以的，没什么要求，只要在那种颜色的最大吸收峰附近都可以不放心的话，你可以做个标准曲线看看有多少干扰

MTT, a yellow tetrazole, is reduced to purple formazan in living cells.[2] A solubilization solution (usually either dimethyl sulfoxide, an acidified ethanol solution, or a solution of the detergent sodium dodecyl sulfate in diluted hydrochloric acid) is added to dissolve the insoluble purple formazan product into a colored solution. The absorbance of this colored solution can be quantified by measuring at a certain wavelength (usually between 500 and 600 nm) by a spectrophotometer. The degree of light absorption depends on the solvent.