The present invention relates to a nucleic acid molecule comprising a nucleotide sequence as set forth in SEQ ID Nos. 1 or 20 or having at least 55% sequence identify therewith and/or capable of hybridising under medium stringency conditions to the complementary sequence of SEQ ID Nos. 1 or 20, or the complementary sequence of said sequences, wherein said nucleotide sequence encodes or is complementary to a sequence which encodes a heat labile alkaline phosphatase and to a recombinant heat labile alkaline comprising: (a) all or a significant part of an amino acid sequence as shown in SEQ ID No. 2; or (b) all or a significant part of an amino acid sequence which has at least 60% sequence identify with SEQ ID No. 2 as well as methods for the manufacture thereof. 1 k AYWNKDAQDALDKQLGIKLREKQAKNVIFFLGDGMSLSTVTAARIYKGG 5ReRP6:17 51 LTGKFEREKISWEEFDFAALSKTYNTDKQ AYLTGVKTNQGV Active site 101 IGLDANTVRTNCSYQLDESLFTYSIAHWFQEAGRSTGVVTSTRVTHATPA 151 GTYAHVADRDWENDSDVVHDREDPEICDDIAEQLVFREPGKNFK VIMGGG 5ReRP6:26 201 RRGFFPEEALDIEDGIPGEREDGK HLITDWLDDKASQGATASYVWNRDDL H23:30 251 LAVDIRNTDYLMGLFSYTHLDTVLTRDAEMDPTLPEMTKVAIEMLTKDEN 301 GFFLLVEGGRIDHMHHANQIRQSLAETLDMEEAVSMALSMTDPEETIILV 351 TADHGHTLTITGYADRNTDILDFAGISDLDDRRYTILDYGSGPGYHITED 401 GKRYEPTEEDLK DINFRYASAAPKHSVTHDGTDVGIWVNGPFAHLFTGVY H23:18 451 EENYIPHALAYAACVGTGRTFCDEK *